EXHIBIT 10.24 CONTINUING GUARANTY

Exhibit 10.24

TO: WELLS FARGO BANK, NATIONAL ASSOCIATION

1.         GUARANTY; DEFINITIONS. In consideration of any credit or other financial accommodation heretofore, now or hereafter extended or made to Medtox Scientific, Inc., Medtox Diagnostics, Inc. and Medtox Laboratories, Inc. ("Borrowers"), or any of them, by WELLS FARGO BANK, NATIONAL ASSOCIATION ("Bank"), and for other valuable consideration, the undersigned New Brighton Business Center LLC ("Guarantor"), jointly and severally unconditionally guarantees and promises to pay to Bank or order, on demand in lawful money of the United States of America and in immediately available funds, any and all Indebtedness of any of the Borrowers to Bank. The term "Indebtedness" is used herein in its most comprehensive sense and includes any and all advances, debts, obligations and liabilities of Borrowers, or any of them, heretofore, now or hereafter made, incurred or created, whether voluntary or involuntary and however arising, whether due or not due, absolute or contingent, liquidated or unliquidated, determined or undetermined, and whether Borrowers may be liable individually or jointly with others, or whether recovery upon such Indebtedness may be or hereafter becomes unenforceable. This Guaranty is a guaranty of payment and not collection.

2.         MAXIMUM LIABILITY; SUCCESSIVE TRANSACTIONS; REVOCATION; OBLIGATION UNDER OTHER GUARANTIES. This is a continuing guaranty and all rights, powers and remedies hereunder shall apply to all past, present and future Indebtedness of each of the Borrowers to Bank, including that arising under successive transactions which shall either continue the Indebtedness, increase or decrease it, or from time to time create new Indebtedness after all or any prior Indebtedness has been satisfied, and notwithstanding the death, incapacity, dissolution, liquidation or bankruptcy of any of the Borrowers or Guarantor or any other event or proceeding affecting any of the Borrowers or Guarantor. This Guaranty shall not apply to any new Indebtedness created after actual receipt by Bank of written notice of its revocation as to such new Indebtedness; provided however, that loans or advances made by Bank to any of the Borrowers after revocation under commitments existing prior to receipt by Bank of such revocation, and extensions, renewals or modifications, of any kind, of Indebtedness incurred by any of the Borrowers or committed by Bank prior to receipt by Bank of such revocation, shall not be considered new Indebtedness. Any such notice must be sent to Bank by registered U.S. mail, postage prepaid, addressed to its office at Minneapolis RCBO, Sixth and Marquette, Minneapolis, MN 55479 , or at such other address as Bank shall from time to time designate. Any payment by Guarantor with respect to the Indebtedness shall not reduce Guarantor's maximum obligation hereunder unless written notice to that effect is actually received by Bank at or prior to the time of such payment. The obligations of Guarantor hereunder shall be in addition to any obligations of Guarantor under any other guaranties of any liabilities or obligations of any of the Borrowers or any other persons heretofore or hereafter given to Bank unless said other guaranties are expressly modified or revoked in writing; and this Guaranty shall not, unless expressly herein provided, affect or invalidate any such other guaranties.

3.         OBLIGATIONS JOINT AND SEVERAL; SEPARATE ACTIONS; WAIVER OF STATUTE OF LIMITATIONS; REINSTATEMENT OF LIABILITY. The obligations hereunder are joint and several and independent of the obligations of Borrowers, and a separate action or actions may be brought and prosecuted against Guarantor whether action is brought against any of the Borrowers or any other person, or whether any of the Borrowers or any other person is joined in any such action or actions. Guarantor acknowledges that this Guaranty is absolute and unconditional, there are no conditions precedent to the effectiveness of this Guaranty, and this Guaranty is in full force and effect and is binding on Guarantor as of the date written below, regardless of whether Bank obtains collateral or any guaranties from others or takes any other action contemplated by Guarantor. Guarantor waives the benefit of any statute of limitations affecting Guarantor's liability hereunder or the enforcement thereof, and Guarantor agrees that any payment of any Indebtedness or other act which shall toll any statute of

limitations applicable thereto shall similarly operate to toll such statute of limitations applicable to Guarantor's liability hereunder. The liability of Guarantor hereunder shall be reinstated and revived and the rights of Bank shall continue if and to the extent that for any reason any amount at any time paid on account of any Indebtedness guaranteed hereby is rescinded or must otherwise be restored by Bank, whether as a result of any proceedings in bankruptcy or reorganization or otherwise, all as though such amount had not been paid. The determination as to whether any amount so paid must be rescinded or restored shall be made by Bank in its sole discretion; provided however, that if Bank chooses to contest any such matter at the request of Guarantor, Guarantor agrees to indemnify and hold Bank harmless from and against all costs and expenses, including reasonable attorneys' fees, expended or incurred by Bank in connection therewith, including without limitation, in any litigation with respect thereto.

4.         AUTHORIZATIONS TO BANK. Guarantor authorizes Bank either before or after revocation hereof, without notice to or demand on Guarantor, and without affecting Guarantor's liability hereunder, from time to time to: (a) alter, compromise, renew, extend, accelerate or otherwise change the time for payment of, or otherwise change the terms of, the Indebtedness or any portion thereof, including increase or decrease of the rate of interest thereon; (b) take and hold security for the payment of this Guaranty or the Indebtedness or any portion thereof, and exchange, enforce, waive, subordinate or release any such security; (c) apply such security and direct the order or manner of sale thereof, including without limitation, a non-judicial sale permitted by the terms of the controlling security agreement, mortgage or deed of trust, as Bank in its discretion may determine; (d) release or substitute any one or more of the endorsers or any other guarantors of the Indebtedness, or any portion thereof, or any other party thereto; and (e) apply payments received by Bank from any of the Borrowers to any Indebtedness of any of the Borrowers to Bank, in such order as Bank shall determine in its sole discretion, whether or not such Indebtedness is covered by this Guaranty, and Guarantor hereby waives any provision of law regarding application of payments which specifies otherwise. Bank may without notice assign this Guaranty in whole or in part. Upon Bank's request, Guarantor agrees to provide to Bank copies of Guarantor's financial statements.

5.         REPRESENTATIONS AND WARRANTIES. Guarantor represents and warrants to Bank that: (a) this Guaranty is executed at Borrowers' request; (b) Guarantor shall not, without Bank's prior written consent, sell, lease, assign, encumber, hypothecate, transfer or otherwise dispose of all or a substantial or material part of Guarantor's assets other than in the ordinary course of Guarantor's business; (c) Bank has made no representation to Guarantor as to the creditworthiness of any of the Borrowers; and (d) Guarantor has established adequate means of obtaining from each of the Borrowers on a continuing basis financial and other information pertaining to Borrowers' financial condition. Guarantor agrees to keep adequately informed from such means of any facts, events or circumstances which might in any way affect Guarantor's risks hereunder, and Guarantor further agrees that Bank shall have no obligation to disclose to Guarantor any information or material about any of the Borrowers which is acquired by Bank in any manner.

6.1        Guarantor waives any right to require Bank to: (a) proceed against any of the Borrowers or any other person; (b) marshal assets or proceed against or exhaust any security held from any of the Borrowers or any other person; (c) give notice of the terms, time and place of any public or private sale or other disposition of personal property security held from any of the Borrowers or any other person; (d) take any action or pursue any other remedy in Bank's power; or (e) make any presentment or demand for performance, or give any notice of nonperformance, protest, notice of protest or notice of dishonor hereunder or in connection with any obligations or evidences of indebtedness held by Bank as security for or which constitute in whole or in part the Indebtedness guaranteed hereunder, or in connection with the creation of new or additional Indebtedness.

6.2       Guarantor waives any defense to its obligations hereunder based upon or arising by reason of: (a) any disability or other defense of any of the Borrowers or any other person; (b) the cessation or limitation from any cause whatsoever, other than payment in full, of the Indebtedness of any of the

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Borrowers or any other person; (c) any lack of authority of any officer, director, partner, agent or other person acting or purporting to act on behalf of any of the Borrowers which is a corporation, partnership or other type of entity, or any defect in the formation of any such Borrower; (d) the application by any of the Borrowers of the proceeds of any Indebtedness for purposes other than the purposes represented by Borrowers to, or intended or understood by, Bank or Guarantor; (e) any act or omission by Bank which directly or indirectly results in or aids the discharge of any of the Borrowers or any portion of the Indebtedness by operation of law or otherwise, or which in any way impairs or suspends any rights or remedies of Bank against any of the Borrowers; (f) any impairment of the value of any interest in any security for the Indebtedness or any portion thereof, including without limitation, the