PLACEMENT AGENCY AGREEMENT

Ladies and Gentlemen:

Acacia Research Corporation, a Delaware corporation (the “ Company ”) proposes, subject to the terms and conditions contained herein and in the Subscription Agreements in the form of Exhibit A attached hereto (the “ Subscription Agreements ”) entered into with the Investors identified therein (each an “ Investor ” and, collectively, the “ Investors ”), to issue and sell up to an aggregate of 9,768,313 units (the “ Units ”), each consisting of (i) one share (the “ Share ” and collectively the “ Shares ”) of common stock, $0.001 par value per share, designated as Acacia Research - CombiMatrix Common Stock (the “ AR - CombiMatrix Common Stock ”), of the Company and (ii) one warrant (the “ Warrant ” and collectively the “ Warrants ”) to purchase 1.2 shares of AR-CombiMatrix Common Stock substantially in the form of Exhibit B attached hereto. The shares issuable upon the exercise of the Warrants and the Placement Agent’s Warrants (as defined in Section 1(a) below) are referred to herein as the “ Warrant Shares ” and, together with the Units, the Shares and the Warrants are referred to herein as the “ Securities .” The Company hereby confirms its agreement with Oppenheimer & Co. Inc. (“ Oppenheimer ”) acting as the placement agent (the “ Placement Agent ”). The Securities are more fully described in the Registration Statement (as hereinafter defined).

1.       Agreement to Act as Placement Agent; Delivery and Payment . On the basis of the representations, warranties and agreements of the Company herein contained, and subject to all the terms and conditions of this Agreement:

(a)      The Placement Agent agrees to act as the Company’s exclusive placement agent to solicit offers for the purchase of all or part of the Units from the Company in connection with the proposed issuance and sale, on a commercially reasonable efforts basis, by the Company of the Units to the Investors (the “ Offering ”). Upon the occurrence of the Closing (as hereinafter defined), the Company shall pay to the Placement Agent by wire transfer of immediately available funds to an account or accounts designated by the Placement Agent an amount equal to seven percent (7.0%) of the gross proceeds received by the Company from the sale of the Units on such Closing Date (as hereinafter defined). In addition, the Company shall issue and sell to the Placement Agent and/or its designees, in addition to the amount set forth above, warrants (the “ Placement Agent’s Warrants ”) to purchase 488,416 shares of Common Stock for a purchase price of $0.01 per warrant. The Placement Agent’s Warrants will entitle the holder thereof for a five-year period commencing on the first day after the six-month anniversary of the Closing Date to purchase 488,416 shares of AR - CombiMatrix Common Stock at an exercise price equal to $1.0875 per share. The Placement Agent’s Warrants shall be in the form attached hereto as Exhibit C . The Company acknowledges and agrees that the Placement Agent’s engagement hereunder is not an agreement by the Placement Agent or any of its affiliates to underwrite or purchase any securities or otherwise provide any financing. Under no circumstances will the Placement Agent be obligated to purchase any Units for its own account and, in soliciting purchases of Units, the Placement Agent shall act solely as the Company’s agent and not as principal. Notwithstanding the foregoing, it is understood and agreed that the Placement Agent (or its affiliates) may, solely at its discretion and without any obligation to do so, purchase Units as principal. The Placement Agent shall have no authority to bind the Company.

(b)      Payment of the purchase price for, and delivery of, the Units shall be made at a closing (the “ Closing ”) at the offices of Greenberg Traurig, LLP, counsel for the Company, located at 650 Town Center Drive, Suite 1700, Costa Mesa, California at 7:00 a.m., local time, on the third or fourth business day (as permitted under Rule 15c6-1 under the Exchange Act) after the determination of the public offering price of the Units (such time and date of payment and delivery being herein called the “ Closing Date ”). All such actions taken at the Closing shall be deemed to have occurred simultaneously.

(c)      Prior to the Closing, the Placement Agent shall cause each Investor to wire directly to an escrow account designated by the Placement Agent an amount equal to the aggregate purchase price for the number of Units such Investor has agreed to purchase.

(d)      On the Closing Date, the Placement Agent shall cause the aggregate purchase price for the Units to be wired from the Investors or the escrow account referred to in Section 1(c) above to an account designated by the Company and the Company shall deliver, or cause the transfer agent for the Units to deliver, to each Investor the number of Units set forth on the signature page to such Investor’s Subscription Agreement, which delivery shall be made, with respect to an Investor, in accordance with the procedures set forth in such Investor’s executed Subscription Agreement.

(e)      The purchases of the Units by each of the Investors shall be evidenced by the execution of a Subscription Agreement substantially in the form attached hereto as Exhibit A

(f)      Prior to the earlier of (i) the date on which this Agreement is terminated and (ii) the Closing Date, the Company shall not, without the prior written consent of the Placement Agent, solicit or accept offers to purchase shares of its AR-CombiMatrix Common Stock or other equity or equity-linked securities of the Company (other than pursuant to the exercise of options or warrants to purchase shares of AR-CombiMatrix Common Stock that are outstanding at the date hereof) otherwise than through the Placement Agent.

2.       Representations and Warranties of the Company . The Company represents and warrants to the Placement Agent and the Investors as of the date hereof and as of the Closing Date, as follows:

(a)       RegistrationStatement . The Company has prepared and filed in conformity with the requirements of the Securities Act of 1933, as amended (the “ Securities Act ”), and published rules and regulations thereunder (the “ Rules and Regulations ”) adopted by the Securities and Exchange Commission (the “ Commission ”) a “shelf” Registration Statement (as hereinafter defined) on Form S-3 (No. 333-133529), which was declared by the Commission to be effective under the Securities Act as of May 26, 2006 (the “ Effective Date ”) including a Base Prospectus, dated as of the Effective Date, relating to the Securities (the “ Base Prospectus ”), and such amendments and supplements thereto as may have been required to the date of this Agreement. The Company will next file with the Commission pursuant to Rule 424(b) under the Securities Act a final prospectus supplement to the Base Prospectus (a ^“ Prospectus Supplement ”) describing the Units and the offering thereof, in such form as has been provided to or discussed with, and approved, by the Placement Agent.

The term “ Registration Statement ” as used in this Agreement means the registration statement (including all exhibits, financial schedules and all documents and information deemed to be a part of the Registration Statement pursuant to Rule 430A or 434(d) under the Securities Act), as of the Effective Date and as amended and/or supplemented to the date of this Agreement. The Registration Statement has been declared effective under the Securities Act and no stop order preventing or suspending the effectiveness of the Registration Statement or suspending or preventing the use of the Prospectus (as defined below) has been issued by the Commission and no proceedings for that purpose have been instituted or, to the Company’s knowledge, are contemplated by the Commission.

The term “ Prospectus ” as used in this Agreement means the Base Prospectus together with the Prospectus Supplement, except that if such Base Prospectus is amended or supplemented prior to the date on which the Prospectus Supplement was first filed pursuant to Rule 424, the term “ Prospectus ” shall refer to the Base Prospectus as so amended or supplemented and as supplemented by the Prospectus Supplement. Any reference herein to the Registration Statement, the Base Prospectus, any Prospectus Supplement or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 (the “ Incorporated Documents ”), which were filed under the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”) and any reference herein to the terms “amend,” “amendment,” or “supplement” with respect to the Registration Statement, the Prospectus Supplement or the Prospectus shall be deemed to refer to and include (i) the filing of any document under the Exchange Act after the Effective Date, or the date of the Prospectus, as the case may be, which is incorporated by reference and (ii) any such document so filed. If the Company has filed an abbreviated registration statement to register additional Securities pursuant to Rule 462(b) under the Rules (the “ 462(b) Registration Statement ”), then any reference herein to the Registration Statement shall also be deemed to include such 462(b) Registration Statement.

(b)       Registration Statement and Prospectus . On the Effective Date, upon the filing or first delivery to the Investors of the Prospectus, as of the date hereof, and at the Closing Date, the Registration Statement (and any post-effective amendment thereto) and the Prospectus (as amended or as supplemented if the Company shall have filed with the Commission any amendment or supplement to the Registration Statement or the Prospectus) complied and will comply, in all material respects, with the requirements of the Securities Act and the Rules and Regulations and the Exchange Act and the rules and regulations of the Commission thereunder and did not at the Effective Date, does not as of the date hereof and will not as of the Closing Date, contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein (in light of the circumstances under which they were made, in the case of the Prospectus) not misleading. Notwithstanding the foregoing, none of the representations and warranties in this paragraph 2(b) shall apply to statements in, or omissions from, the Registration Statement or the Prospectus, or any amendment or supplement thereto made in reliance upon, and in conformity with, information herein or otherwise furnished in writing by or on behalf of the Placement Agent to the Company expressly for use in the Registration Statement or the Prospectus or any amendment or supplement thereto. The Incorporated Documents, at the time they became effective or were filed with the Commission, complied in all material respects with the requirements of the Exchange Act and did not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. The Company has not distributed and will not distribute, prior to the completion of the distribution of the Securities, any offering material in connection with the offering and sale of the Securities, other than the Registration Statement and the Prospectus.

(c)       Subsidiaries . The Company has no significant subsidiaries (as such term is defined in Rule 1-02 of Regulation S-X promulgated by the Commission) other than as listed in Schedule I attached hereto (collectively, the “ Subsidiaries ”). All of the issued and outstanding shares of capital stock of each of the Subsidiaries have been duly and validly authorized and issued and are fully paid, nonassessable and free of preemptive and similar rights to subscribe for or purchase securities, and, except as listed on Schedule I attached hereto or otherwise described in the Registration Statement and Prospectus, the Company owns directly or indirectly, free and clear of any security interests, claims, liens, proxies, equities or other encumbrances, all of the issued and outstanding shares of such stock.

(d)       Financial _Statements . The consolidated financial statements of the Company, together with the related schedules and notes thereto, set forth or incorporated by reference in the Registration Statement and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and fairly present, in all material respects, (i) the consolidated financial condition of the Company and its Subsidiaries as of the dates indicated and (ii) the consolidated results of operations, stockholders’ equity and changes in cash flows of the Company and the Subsidiaries for the periods therein specified; and such financial statements and related schedules and notes thereto, comply, in all material respects, as to form with the applicable accounting requirements under the Securities Act and have been prepared in conformity with United States generally accepted accounting principles, consistently applied throughout the periods involved (except as otherwise stated therein and subject, in the case of unaudited financial statements, to the absence of footnotes and normal year-end adjustments). No other financial statements or schedules are required by the Securities Act and the Rules and Regulations to be included in the Registration Statement or Prospectus.

(e)       Independent Accountants . PricewaterhouseCoopers, LLP (the ^“ Auditors ”), whose report with respect to the audited consolidated financial statements and schedules of the Company and its Subsidiaries included in the Prospectus, or the Registration Statement, or incorporated by reference therein is, and during the periods covered by its reports, was an independent public accounting firm within the meaning of the Securities Act and the Rules and Regulations.

(f)       Organization . Each of the Company and its Subsidiaries has been duly incorporated or otherwise organized and is validly existing as a corporation in good standing under the laws of its jurisdiction of incorporation or organization (as applicable). Each of the Company and its Subsidiaries has full corporate power and authority to own, lease and operate its properties and assets and to conduct its business as described in the Registration Statement and Prospectus, and is duly qualified to do business as a foreign corporation and is in good standing in each jurisdiction in which it owns or leases real property or in which the conduct of its business makes such qualification necessary, except where the failure to be so qualified or be in good standing, as the case may be, would not, individually or in the aggregate, have or reasonably be expected to result in, a material adverse effect upon the business, prospects, properties, operations, condition (financial or otherwise) or results of operations of the Company and its Subsidiaries, taken as a whole (a “ Material Adverse Effect ”).

(g)       No Material Adverse Effect . Except as set forth in the Registration Statement or the Prospectus, subsequent to the respective dates as of which information is given in the Registration Statement and the Prospectus, there has not been (i) any material adverse change in the business, properties, management, financial condition or results of operations of the Company and its subsidiaries taken as a whole, including any material loss or interference with its respective business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, (ii) any transaction that is material to the Company and its Subsidiaries taken as a whole, (iii) any obligation, direct or contingent (including any off balance sheet obligations), incurred by the Company or its Subsidiaries, which is material to the Company and its Subsidiaries taken as a whole, (iv) any change in the capital stock or outstanding indebtedness of the Company or its Subsidiaries (subject to the issuance of shares of Common Stock upon exercise of stock options or warrants disclosed as outstanding in the Registration Statement and Prospectus and the grant of options under existing stock option plans described in the Registration Statement and Prospectus) or (v) any dividend or distribution of any kind declared, paid or made on the capital stock of the Company.

(h)       Legal Proceedings . Except as set forth in the Registration Statement and the Prospectus, there is not pending or, to the knowledge of the Company, threatened or contemplated, any action, suit or proceeding to which the Company or any of its Subsidiaries is a party or of which any property or assets of the Company or any of its Subsidiaries is the subject before or by any court or governmental agency, authority or body, or any arbitrator, which, individually or in the aggregate, would reasonably be expected to result in any Material Adverse Effect or materially and adversely affect the ability of the Company to perform its obligations under this Agreement and the Subscription Agreements.

(i)       Sufficiency of Disclosure . There are (i) no current or pending legal, governmental or regulatory actions, suits or proceedings that are required under the Securities Act to be described in the Registration Statement and Prospectus that have not been so described and (ii) there are no affiliate transactions, off-balance sheet transactions, contracts, licenses, agreements, leases or other documents of a character required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not so described or filed as required.

(j)       Due Authorization and Enforceability . The Company has full legal power and authority to enter into this Agreement and the Subscription Agreements and to consummate the transactions contemplated hereby and thereby. This Agreement and each of the Subscription Agreements have been duly authorized, executed and delivered by the Company, and constitute valid, legal and binding obligations of the Company, enforceable in accordance with their terms, except as rights to indemnity hereunder may be limited by applicable laws and except as such enforceability may be limited by bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights and remedies of creditors generally or subject to general principles of equity.

(k)       The Shares . The Shares have been duly and validly authorized by the Company and, when issued, delivered and paid for in accordance with the terms of this Agreement, will have been duly and validly issued and will be fully paid and nonassessable; and the capital stock of the Company, including the AR-CombiMatrix Common Stock, conforms to the description thereof in the Registration Statement and Prospectus. Except as otherwise stated in the Registration Statement and Prospectus, there are no preemptive rights or other rights to subscribe for or to purchase, or any restriction upon the voting or transfer of, any shares of AR -CombiMatrix Common Stock pursuant to the Company’s charter, bylaws or any agreement or other instrument to which the Company is a party or by which the Company is bound that have not been waived or complied with.

(l)       The Warrants and the Placement Agent’s Warrants . The Company has the full right, power and authority to enter into the Warrants and the Placement Agent’s Warrants and to perform and discharge its obligations thereunder. The Warrants and the Placement Agent’s Warrants have been duly and validly authorized by the Company and upon delivery to the Investors at the Closing Date will be duly issued and will constitute legal, valid and binding obligations of the Company, enforceable in accordance with their terms, except as such enforceability may be limited by bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights and remedies of creditors generally or subject to general principles of equity. The Warrant Shares have been duly authorized and reserved for issuance upon the exercise of the Warrants and the Placement Agent’s Warrants and when issued upon payment of the exercise price therefor will be validly issued, fully paid and nonassessable.

(m)       No Conflicts . The execution, delivery and performance by the Company of this Agreement, the Warrants and the Placement Agent’s Warrants, and each of the Subscription Agreements and the consummation of the transactions herein and therein contemplated, including the issuance and sale of the Securities, will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default (or an event which with notice or lapse of time or both would constitute a default) under, or require any consent or waiver under, or result in the execution of any lien, charge or encumbrance upon any properties or assets of the Company or its Subsidiaries pursuant to the terms of, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its Subsidiaries is a party or by which the Company or any of its Subsidiaries is bound or to which any of the property or assets of the Company or any of its Subsidiaries is subject, (ii) result in any violation of the provisions of the charter or by-laws of the Company or any of its Subsidiaries or (iii) result in any violation of any franchise, license, permit, statute, law, rule or regulation applicable to the Company or any judgment, order or decree of any court or governmental agency or body having jurisdiction over the Company or any of its Subsidiaries or any of their properties or assets, except, in the case of each of clauses (i) and (iii) above, for any such conflict, breach, violation, default, lien, charge or encumbrance that would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(n)       No Consents Required . No consent, approval, authorization, filing with or order of or registration with, any court or governmental agency or body, or approval of the shareholders of the Company, is required for the execution, delivery and performance of this Agreement, the Warrants and the Placement Agent’s Warrants, and each of the Subscription Agreements or for the consummation of the transactions contemplated hereby and thereby, including the issuance or sale of the Securities by the Company, except such as have been obtained or made, and such as may be required under the securities, or blue sky, laws of any jurisdiction in connection with the offer and sale of the Units by the Company in the manner contemplated herein and in the Registration Statement and the Prospectus.

(o)       Capitalization . All of the issued and outstanding shares of capital stock of the Company, including the outstanding shares of AR-CombiMatrix Common Stock, are duly authorized and validly issued, fully paid and nonassessable, have been issued in compliance with all federal and state securities laws, were not issued in violation of or subject to any preemptive rights or other rights to subscribe for or purchase securities that have not been waived in writing. As of the date hereof and as of the Closing Date, the Company has or will have, as the case may be, an authorized, issued and outstanding capitalization as is set forth in the Registration Statement and the Prospectus (subject, in each case, to the issuance of shares of Common Stock upon exercise of stock options and warrants disclosed as outstanding in the Registration Statement and the Prospectus and grant of options under existing stock option plans described in the Registration Statement and the Prospectus, and such authorized capital stock conforms to the description thereof set forth in the Registration Statement and the Prospectus. Except as described in the Registration Statement and the Prospectus, as of the date referred to therein, the Company did not have outstanding any options, warrants, agreements, contracts or other rights in existence to purchase or acquire from the Company or any Subsidiary of the Company any shares of the capital stock of the Company or any Subsidiary of the Company.

(p)       Title to Real and Personal Property . The Company and each of its Subsidiaries has good and valid title to all property (whether real or personal) described in the Registration Statement and Prospectus as being owned by each of them, in each case free and clear of all liens, claims, security interests, other encumbrances or defects except such as are described in the Registration Statement and the Prospectus and those that do not materially and adversely affect the value of such property and do not materially interfere with the use made of such property by the Company. All of the property described in the Registration Statement and the Prospectus as being held under lease by the Company or a Subsidiary are held thereby under valid, subsisting and enforceable leases.

(q)       Title to Intellectual Property . The Company and its Subsidiaries own, possess, license or have other rights to use all foreign and domestic patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights, licenses, inventions, trade secrets, technology, Internet domain names, know-how and other intellectual property, necessary for the conduct of CombiMatrix Group’s (as defined in the Prospectus) businesses as now conducted or as proposed in the Prospectus to be conducted (collectively, the “ Intellectual Property ”). Except as set forth in the Prospectus, (a) the Company has not received written notice, and has no knowledge of, any rights of third parties to any such Intellectual Property; (b) to the Company’s knowledge, there is no infringement by third parties of any such Intellectual Property; (c) there is no pending or, to the Company’s knowledge _, threatened action, suit, proceeding or claim by others challenging the Company’s and its Subsidiaries’ rights in or to any such Intellectual Property; (d) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property; (e) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others that CombiMatrix Group infringes or otherwise violates any patent, trademark, copyright, trade secret or other proprietary rights of others; (f) to the Company’s knowledge, there is no third-party U.S. patent or published U.S. patent application which contains claims for which an Interference Proceeding (as defined in 35 U.S.C. § 135) has been commenced against any patent or patent application which constitutes the Intellectual Property described in the Prospectus; and (g) the CombiMatrix Group has taken all steps necessary to perfect its ownership of the Intellectual Property, in each of clauses (a)-(g) except for such infringement, conflict or action which would not, singularly or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(r)       No Violation or Default . Neither the Company nor any of its Subsidiaries is (i) in violation of any provision of its charter or bylaws or similar organizational documents, (ii) is in default in any respect, and no event has occurred which, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant, or condition of any indenture, contract, lease, mortgage, deed of trust, note agreement, loan agreement or other agreement, obligation, condition, covenant or instrument to which it is a party or by which it is bound or to which any of its property or assets is subject, or (iii) is in violation in any respect of any statute, law, rule, regulation, ordinance, judgment, order or decree of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company, its Subsidiaries or any of its properties of which it has knowledge, as applicable, except, with respect to clauses (ii) and (iii), any violations or defaults which, singularly or in the aggregate, would not reasonably be expected to result in a Material Adverse Effect.

(s)       Permits . The Company and each of its Subsidiaries has made all filings, applications and submissions required by, and possesses all approvals, licenses, certificates, certifications, clearances, consents, exemptions, marks, notifications, orders, permits and other authorizations issued by, the appropriate federal, state or foreign regulatory authorities necessary to conduct its businesses as described in the Registration Statement and the Prospectus (collectively, “ Permits ”), except for such Permits the failure of which to obtain would not reasonably be expected to result in a Material Adverse Effect, and is in compliance with the terms and conditions of all such Permits; all of such Permits held by the Company and each of its Subsidiaries are valid and in full force and effect; there is no pending or, to its knowledge, threatened action, suit, claim or proceeding which may cause any such Permit to be limited, revoked, cancelled, suspended, modified or not renewed, except for such limitations, revocations, cancellations, suspensions, modifications or non-renewals that would not reasonably be expected to result in a Material Adverse Effect; and the Company and each of its Subsidiaries has not received any notice of proceedings relating to the limitation, revocation, cancellation, suspension, modification or non-renewal of any such Permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Effect, whether or not arising from transactions in the ordinary course of business and has no reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course.

(t)       Taxes . The Company and its Subsidiaries have timely filed all federal, state, local and foreign income and franchise tax returns (or timely filed applicable extensions therefore) required to be filed and are not in default in the payment of any taxes which were payable pursuant to said returns or any assessments with respect thereto, other than any which the Company or any of its Subsidiaries is contesting in good faith and for which adequate reserves have been provided.

(u)       Listing . The AR-CombiMatrix Common Stock (including the Shares and the Warrant Shares) is registered pursuant to Section 12(g) of the Exchange Act and the Company, in the two years preceding the date hereof, has not received any notification (written or oral) from the Nasdaq Global Market, any stock exchange, market or trading facility on which the AR-CombiMatrix Common Stock is or has been listed (or on which it has been quoted) to the effect that the Company is not in compliance with the listing or maintenance requirements of such exchange, market or trading facility. The Company shall comply with all requirements of the Nasdaq Global Market with respect to the issuance of the Securities and shall use its best efforts to have the Shares and the Warrant Shares listed on the Nasdaq Global Market on or before the Closing Date.

(v)       Internal Controls . The Company and each of its Subsidiaries maintains a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(w)       Disclosure Controls . The Company has established and maintains disclosure controls and procedures (as such term is defined in Rule 13a-15e and 15d-15e under the Exchange Act), which (i) are designed to ensure that material information relating to the Company is made known to the Company’s principal executive officer and its principal financial officer by others within those entities, particularly during the periods in which the periodic reports required under the Exchange Act are being prepared; (ii) provide for the periodic evaluation of the effectiveness of such disclosure controls and procedures as of the end of each of the Company’s quarterly and annual fiscal periods; and (iii), as of the end of the periods covered by each periodic report filed under the Exchange Act and incorporated by reference into the Prospectus, were effective in all material respects to perform the functions for which they were established. The Company’s auditors and the Audit Committee of the Board of Directors have been advised of (i) any significant deficiency in the design or operation of internal controls which could adversely affect the Company’s ability to record, process, summarize and report financial data or any material weaknesses in internal controls; or (ii) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal controls. Since the date of the most recent evaluation of such disclosure controls and procedures, there have been no changes that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting, including any corrective actions with regard to significant deficiencies and material weaknesses.

(x)       No Undisclosed Relationships . No relationship, direct or indirect, exists between or among the Company on the one hand and the directors, officers, stockholders, customers or suppliers of the Company on the other hand which is required to be described in the Prospectus and which is not so described.

(y)       No Registration Rights . Except as described in the Prospectus, no person or entity has the right, contractual or otherwise, to require registration of shares of AR-CombiMatrix Common Stock or other securities of the Company because of the filing or effectiveness of the Registration Statement or otherwise, except for persons and entities who have expressly waived such right or who have been given proper notice and have failed to exercise such right within the time or times required under the terms and conditions of such right, and the Company is not required to file any registration statement for the registration of any securities of any person or register any such securities pursuant to any other registration statement filed by the Company under the Securities Act for a period of at least 180 days after the Effective Date.

(z)       Sarbanes-Oxley Act . The principal executive officer and principal financial officer of the Company have made all certifications required by Sections 302 and 906 of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith (the “ Sarbanes:Oxley Act ”) with respect to all reports, schedules, forms, statements and other documents required to be filed by it with the Commission, and the statements contained in any such certification are complete and cor ^r ect. The Company, and to its knowledge after due inquiry, all of the Company’s directors or officers, in their capacities as such, is in compliance in all material respects with all applicable effective provisions of the Sarbanes-Oxley Act (and intends to comply with all applicable provisions that are not yet effective upon effectiveness).

(aa)          Compliance with Environmental Laws . (i) The Company and each of its Subsidiaries is in compliance in all material respects with all rules, laws and regulation relating to the use, treatment, storage and disposal of toxic substances and protection of human health and safety or the environment (“ Environmental Laws ”) which are applicable to its business, except where the failure to comply would not reasonably be expected to result in a Material Adverse Effect; (ii) neither the Company nor its Subsidiaries has received any written notice from any governmental authority or third party of an asserted claim under Environmental Laws; (iii) the Company and each of its Subsidiaries has received all material permits, licenses or other approvals required of it under applicable Environmental Laws to conduct its business and is in compliance with all material terms and conditions of any such permit, license or approval, except where the failure to receive or comply would not reasonably be expected to result in a Material Adverse Effect; (iv) to the Company’s knowledge after reasonable due inquiry, no facts currently exist that will require the Company or any of its Subsidiaries to make future material capital expenditures to comply with Environmental Laws; and (v) no property which is or has been owned, leased or occupied by the Company or its Subsidiaries has been designated as a Superfund site pursuant to the Comprehensive Environmental Response, Compensation of Liability Act of 1980, as amended (42 U.S.C. Section 9601, et. seq,) (“ CERCLA ”) or otherwise designated as a contaminated site under applicable state or local law. Neither the Company nor any of its Subsidiaries has been named as a “potentially responsible party” under CERCLA.

(bb)    Compliance with ERISA . Each of the Company and its Subsidiaries has fulfilled its obligations, if any, under the minimum funding standards of Section 302 of the United States Employee Retirement Income Security Act of 1974 (“ ERISA ”) and the regulations and published interpretations thereunder with respect to each “ plan ” (as defined in Section 3(3) of ERISA and such regulations and published interpretations) in which employees of the Company and its Subsidiaries are eligible to participate and each such plan is in compliance in all material respects with the presently applicable provisions of ERISA and such regulations and published interpretations. No “ prohibited transaction ” (as defined in Section 406 of ERISA, or Section 4975 of the Internal Revenue Code of 1986, as amended from time to time (the “ Code ”)) has occurred with respect to any employee benefit plan which could reasonably be expected to result in a Material Adverse Effect. The Company and each of its Subsidiaries has not incurred any unpaid liability to the Pension Benefit Guaranty Corporation (other than for the payment of premiums in the ordinary course) or to any such plan under Title IV of ERISA,

(cc)    No Labor Disputes . No labor problem or dispute with the employees of the Company or any of its Subsidiaries exists or, to the Company’s knowledge, is threatened or imminent, which would reasonably be expected to result in a Material Adverse Effect. The Company is not aware that any key employee or significant group of employees of the Company or any of its Subsidiaries plans to terminate employment with the Company or any such Subsidiary.

(dd)    Insurance . The Company and each of its Subsidiaries is insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which they are engaged or propose to engage after giving effect to the transactions described in the Prospectus; all policies of insurance and fidelity or surety bonds insuring the Company and each of its Subsidiaries and their businesses, assets, employees, officers and directors are in full force and effect; the Company and each of its Subsidiaries is in compliance with the terms of such policies and instruments in all material respects; and the Company and each of its Subsidiaries has no reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that is not materially greater than the current cost, except where the failure to obtain would not reasonably be expected to result in a Material Adverse Effect.

(ee)    No Stabilization . Neither the Company nor any of its Subsidiaries nor, to its knowledge after reasonable due inquiry, any of their officers, directors, affiliates or controlling persons has taken or will take, directly or indirectly, any action designed or intended to stabilize or manipulate the price of any security of the Company.

(ff)    Investment Company Act . Neither the Company nor any of its Subsidiaries is or, after giving effect to the offering and sale of the Securities and the application of the proceeds thereof as described in the Prospectus, will be required to register as an ^“ investment company” as defined in the Investment Company Act of 1940, as amended.

(gg)    No Broker’s Fees . Neither the Company nor any of its Subsidiaries is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against the Company or its Subsidiaries or the Placement Agent for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Securities.

(hh)    Contracts . Each description of a contract, document or other agreement in the Registration Statement and the Prospectus accurately reflects in all material respects the terms of the underlying contract, document or other agreement. Each contract, document or other agreement described in the Registration Statement and Prospectus or listed in the exhibits to the Registration Statement or incorporated therein by reference is in full force and effect, unless validly terminated in accordance with the provisions thereof, and is valid and enforceable by and against the Company or its Subsidiary, as the case may be, in accordance with its terms, except as such enforceability may be limited by bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights and remedies of creditors generally and subject to general principles of equity, Neither the Company nor any of its Subsidiaries, if a Subsidiary is a party, nor to the Company’s knowledge, any other party, is in default in the observance or performance of any term or obligation to be performed by it under any such agreement, and no event has occurred which with notice or lapse of time or both would constitute such a default, in any such case which default or event, individually or in the aggregate, would reasonably be expected to result in a Material Adverse Effect.

(ii)    Forward-Looking Statements . No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Registration Statement and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(jj)    Corporate Records . All existing minute books of the Company and each of its Subsidiaries, including all existing records of all meetings and actions of the board of directors (including, Audit, Compensation and Nomination/Corporate Governance Committees) and stockholders of the Company through the date of the latest meeting and action (collectively, the “ Corporate Records ”) have been made available to the Placement Agent and counsel for the Placement Agent. All such Corporate Records are complete in all material respects and accurately and fairly reflect, in reasonable detail, all transactions referred to in such Corporate Records.

(kk)    Foreign Corrupt Practices . Neither the Company nor any of its Subsidiaries, nor, to the knowledge of the Company after reasonable due inquiry, any director, officer, agent or employee of the Company or its Subsidiaries, has, directly or indirectly, while acting on behalf of the Company or its Subsidiaries (i) used any corporate funds for unlawful contributions, gifts, entertainment or other unlawful expenses relating to political activity; (ii) made any unlawful payment to foreign or domestic government officials or employees or to foreign or domestic political parties or campaigns from corporate funds; (iii) violated any provision of the Foreign Corrupt Practices Act of 1977, as amended; (iv) made any other unlawful bribe, rebate, payoff, influence, kickback or payment to any foreign or domestic government official or em ^p loyee.

(ll)    Off-Balance Sheet Arrangements . There are no material off balance sheet arrangements (as defined in Item 303 of Regulation S-K) that have or would reasonably be likely to have a material current or future effect on the Company’s financial condition, revenues or expenses, changes in financial condition, results of operations, liquidity, capital expenditures or capital resources, including those off-balance sheet transactions described in the Commission’s Statement about Management’s Discussion and Analysis of Financial Conditions and Results of Operations (Release Nos 33-8056; 34-45321; FR-61), required to be described in the Prospectus which have not been so described.

(mm)    Regulatory Filings . Each of the Company and its Subsidiaries has filed with the applicable regulatory authorities all filings, declarations, listings, registrations, reports and submissions required to be filed;   all such filings, declarations, listings, registrations, reports or submissions were in compliance with applicable laws when filed and no deficiencies have been asserted by any applicable regulatory authority with respect to any such filings, declarations, listings, registrations, repots or submissions. To the Company’s knowledge after reasonable due inquiry, there are no affiliations or associations between any member of the National Association of Securities Dealers, Inc. (the “ NASD ”) and any of the Company’s officers, directors or any five percent (5%) or greater shareholders of the Company, except as set forth in the Registration Statement and the Prospectus or otherwise disclosed in writing to the Placement Agent.

Any certificate signed by any officer of the Company and delivered to the Placement Agent or to counsel for the Placement Agent shall be deemed a representation and warranty by the Company to the Placement Agent and the Investors as to the matters covered thereby.

3.       Delivery and Payment .   On the Closing Date, in accordance with the terms and conditions of each Investor’s respective Subscription Agreement, the Company shall sell to, and the Investor(s) shall purchase, the number of Units reflected on such Investor’s Subscription Agreement against payment by such Investor of such Investor’s aggregate purchase price therefor reflected in the Investor’s Subscription Agreement.

4.       Covenants . The Company covenants and agrees with the Placement Agent as follows:

(a)       Effectiveness . The Registration Statement has become effective, and if Rule 430A is used or the filing of the Prospectus Supplement is otherwise required pursuant to Rule 424(b), the Company shall prepare the Prospectus Supplement in a form approved by the Placement Agent and file such Prospectus pursuant to Rule 424(b) not later than the Commission’s close of business on the business day following the execution and delivery of this Agreement, or, if applicable, such earlier time as may be required by the Rules and Regulations.

(b)       Amendments or Supplements; Free Writing Prospectuses . The Company will not, during such period as the Prospectus would be required by law to be delivered in connection with sales of the Units by the Placement Agent or a dealer in connection with the offering contemplated by this Agreement, file any amendment or supplement to the Registration Statement or the Prospectus, except as required by law, unless a copy thereof shall first have been submitted to the Placement Agent within a reasonable period of time prior to the filing thereof and the Placement Agent shall not have reasonably objected thereto in good faith. The Company represents and agrees that it has not made and will not, make any offer relating to the Units that would constitute a “free writing prospectus” as defined in Rule 405 under the Securities Act (“ Issuer Free Writing Prospectus ”).

(c)       Notice to Placement Agent . The Company agrees (i) for so long as the delivery of a prospectus is required in connection with the offering or sale of the Securities, to advise the Placement Agent promptly after it receives notice thereof, of the time when any post effective amendment to the Registration Statement has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed and to furnish the Placement Agent with copies thereof, (ii) to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 15 or 15(d) of the Exchange Act subsequent to the date of the Prospectus Supplement and for so long as the delivery of a prospectus is required in connection with the offering or sale of the Units; (iii) to advise the Placement Agent, promptly after it receives notices thereof, (x) of any request by the Commission to amend the Registration Statement or to amend or supplement the Prospectus or for additional information with respect thereto, (y) of the issuance by the Commission, of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or any order directed at any document incorporated by reference therein or any amendment or supplement thereto or any order preventing or suspending the use of the Prospectus or any amendment or supplement thereto, or (z) of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the institution or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statement or the Prospectus or for additional information; and, (iv) in the event of the issuance of any stop order or of any order preventing or suspending the use of the Prospectus or suspending any such qualification, promptly to use its reasonable best efforts to obtain the withdrawal of such order.

(d)       Ongoing Compliance of the Prospectus . If, at any time when a Prospectus relating to the Securities is required to be delivered under the Act, the Company becomes aware of the occurrence of any event as a result of which the Prospectus, as then amended or supplemented, would, in the reasonable judgment of counsel to the Company or counsel to the Placement Agent, include any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or the Registration Statement, as then amended or supplemented, would, in the reasonable judgment of counsel to the Company or counsel to the Placement Agent, include any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein not misleading, or if for any other reason it is necessary, in the reasonable judgment of counsel to the Company or counsel to the Placement Agent, at any time to amend or supplement the Prospectus or the Registration Statement to comply with the Act or the Rules and Regulations, the Company will promptly notify the Placement Agent and, subject to Section 4(b) hereof, will promptly prepare and file with the Commission, at the Company’s expense, an amendment to the Registration Statement or an amendment or supplement to the Prospectus that corrects such statement or omission or effects such compliance and will deliver to the Placement Agent, without charge, such number of copies thereof as the Placement Agent may reasonably request. The Company consents to the use of the Prospectus or any amendment or supplement thereto by the Placement Agent, and the Placement Agent agrees to provide to each Investor, prior to the Closing, a copy of the Prospectus and any amendments or supplements thereto.

(e)       Delivery of Copies . To deliver promptly to the Placement Agent and its counsel such number of the following documents as the Placement Agent shall reasonably request: (i) conformed copies of the Registration Statement as originally filed with the Commission and each amendment thereto (in each case excluding exhibits), (ii) so long as a prospectus relating to the Securities is required to be delivered under the Securities Act, as many copies of the Prospectus or any amendment or supplement thereto; (iii) any document incorporated by reference in the Prospectus and (iv) all correspondence to and from, and all documents issued to and by, the Commission in connection with the registration of the Securities under the Securities Act. The Company will pay the expenses of printing or other production of all documents relating to the Offering.

(f)       Use of Proceeds . The Company will apply the net proceeds from the sale of the Securities in the manner set forth in the Prospectus under the heading “Use of Proceeds”.

(g)       Reports . During a period of three years commencing with the date hereof, the Company will furnish to the Placement Agent, copies of all periodic and special reports furnished to the stockholders of the Company and all information, documents and reports filed with the Commission, the NASD, Nasdaq or any securities