Filed by Automated Filing Services Inc. (604) 609-0244 - Response Biomedical Corp. - Exhibit 4.12






 IRREVOCABLE GUARANTEE AGREEMENT 


THIS AGREEMENT MADE EFFECTIVE AS OF THE 13TH DAY OF NOVEMBER 2002 (the "Effective Date").



BETWEEN:



  
    
       RESPONSE BIOMEDICAL CORP., a company incorporated
        under the laws of British Columbia having its head office at 8855 Northbrook
        Court, Burnaby, British Columbia, V5J 5J1 

       (the "Company") 

    

  




AND:



  
    
       MENDERES HOLDING AG, c/o Bank Sarasin &
        Cie, Elisabethenstrasse 62 CH, 4002 Basel, Switzerland

       (the "Guarantor")

    

  



 WHEREAS: 

 A.                the
  Company is entering into a line of credit agreement with The Toronto-Dominion
  Bank ("the "Creditor"), evidenced by the materials attached as Schedule "A"
  for a total of US$500,000 and referred to herein as the "Credit Line ", contingent
  upon the issuance of a suitable standby letter of credit ("LC") to the Creditor
  by Bank Sarasin Elisabethenstrasse 62 CH, 4002 Basel, Switzerland; 

 B.                he
  Guarantor has agreed to guarantee the LC by providing an unconditional and irrevocable
  guarantee for the amount of US$500,000 (the "Guarantee") to Bank Sarasin expiring
  at the office the Creditor on the close of business September 30, 2003; 

 C.                the
  Guarantor has agreed to accept common share purchase warrants (the "Warrants")
  providing the Guarantor the right to purchase 700,621 common shares without
  par value (the "Shares") in the capital stock of the Company as consideration
  for providing the Guarantee, such Warrants to be exercisable at a price of Cdn
  $0.45 per Share and the total aggregate number of Shares calculated based
  on the Bank of Canada Noon Exchange Rate on the effective date of this agreement,
  of C$/US$1.5764; 

 D.                the
  Guarantor is a person to whom the Company may issue securities pursuant to the
  exemption (the "Exemptions") provided by Multilateral Instrument #45-103 of
  the British Columbia Securities Act, Rules, Regulations, Instruments or Notices;
  and 

 E.                the
  Warrants will be issued pursuant to the Exemptions and that the Company is relying
  on the Exemptions from the requireme4ts to provide the purchaser with a prospectus
  and to sell securities through a person registered to sell securities under
  the B.C. Securities Act and, as a consequence of acquiring securities pursuant
  to the Exemptions, certain protections, rights and remedies provided by the
  B.C. Securities Act, including statutory rights of rescission or damages, will
  not be available to the purchaser. 

                    NOW
  THEREFORE THIS AGREEMENT WITNESSETH THAT in consideration of the mutual covenants
  and agreements herein contained, the receipt and sufficiency of which is hereby
  acknowledged, the parties covenant and agree with each other (the "Agreement")
  as follows:





-2- 

	l. 	On the basis of the representations
        and warranties of the Guarantor contained in this Agreement and subject
        to the terms of this Agreement, the Company agrees to issue the Warrants
        to or at the direction of the Guarantor as full consideration for providing
        the Guarantee.

	 	 
	2. 	For the term of the Guarantee, the Company
        agrees to inform the Guarantor of the Credit Line balance by e-mail or
        fax on the last business day of each calendar month.

	 	 
	3.	This Agreement is subject to all necessary
        approvals of the TSX Venture Exchange (the "Exchange") and the B.C. Securities
        Commission (the "Regulators").

	 	 
	4. 	Subject to the Creditor having first
        accepted a LC from Bank Sarasin and the Creditor and the Company executing
        the Credit Line, the Company shall deliver a warrant certificate representing
        the Warrants to the Guarantor at his address shown on the first page of
        this Agreement within ten days of receiving written notice of the last
        of the approvals of the Regulators.

	 	 
	5.	The Guarantor acknowledges that the
        Shares will be subject to a four (4) month hold period from the
        date of the issuance of the Warrants imposed by the Exchange and by the
        operation of applicable securities rules or by applicable securities regulatory
        bodies, and that a share certificate issued within four months of issuing
        the Warrants, as a result of exercising the Warrants, will bear legends
        to that effect.

	 	 
	6. 	The Guarantor acknowledges that this
        Agreement is not being entered into and the Warrants are not being acquired
        by the Guarantor as a result of any material information about the Company's
        affairs that has not been publicly disclosed.

	 	 
	7.	 In the event of any subdivision, consolidation
        or other change in the share capital of the Company prior to the issuance
        of the Warrants, the number of Warrants issued pursuant to this Agreement
        shall be adjusted in accordance with such subdivision, consolidation or
        other change in the share capital of the Company.

	 	 
	8. 	Time shall be of the essence in this
        Agreement.

	 	 
	9. 	This Agreement is subject to, governed
        by and construed in accordance with the laws of the Province of British
        Columbia.

	 	 
	10.	All references to funds in this Agreement
        are in Canadian funds unless otherwise noted.

	 	 
	11.	 This Agreement shall enure to
        the benefit of and be binding upon the parties hereto and their respective
        heirs, executors, administrators, successors and assigns.

	 	 
	12.	The parties hereto agree to execute
        and deliver all such further documents and other writings of any kind
        whatsoever and all such further acts and things as are reasonably required
        to carry out the full intent and meaning of this Agreement.

	 	 
	13.	Whenever the singular or masculine is
        used in this Agreement the same shall be deemed to include the plural
        or the feminine or the body corporate as the context may require.

	 	 
	14.	This Agreement constitutes the entire
        agreement between the parties and there are no representations, warranties,
        covenants or agreements collateral hereto other than as contained herein.












 -3-

	15. 	This Agreement may be signed in as many counterparts
        as may be deemed necessary, each of which so signed shall be deemed to
        be an original, and all such counterparts together shall constitute one
        and the same instrument. 



IN WITNESS WHEREOF the parties have executed this written Agreement effective
  as of the Effective Date. 

 SIGNED, SEALED AND DELIVERED BY 

RESPONSE BIOMEDICAL CORP. per: 

  /s/ William J. Radvak

  Authorized Signatory 

 Name of Signatory: William J. Radvak  


Title of Signatory: President and C.E.O.	


	 SIGNED, SEALED & DELIVERED by 	)	 
	 MENDERES HOLDING AG 	)	 
	 in the presence of: 	)	 
	 	)	 
	/s/
      Eva Schmidlin    	)	MENDERES HOLDING AG
	 Signature of Witness 	)	 
	 	)	 
	Name: /s/ Eva Schmidlin                                                          	)	Per:  Hans E. Moppert
	 	)	 
	Address: c/o Bank Sarasin                                                    	)	/s/ Hans
      E. Moppert                                                   
	 	)	Duly Authorized Signatory of the Guarantor
	Occupation: Secretary of the Group Executive Docs.       	)	 
	                    	)	Chairman of the Board












-4-


 SCHEDULE A  

 1.               Standby
  Letter of Credit issued by Bank Sarasin to The Toronto-Dominion Bank 

 2.               Line
  of Credit Agreement between the Company and The Toronto-Dominion Bank 












	   	The Toronto Dominion Bank
	 	Ms. Kathrin Teichrieb, Analyst
	 	2nd Floor, 700 West Georgia Street
	 	P.O. Box 10001 - Pacific Centre
	 	Vancouver, BC V7Y 1A2
	 	Canada
	 	 
	 	Basel, 14th November 2002
	 	AFLI / 7268


 IRREVOCABLE STANDBY LETTER OF CREDIT NO. 5952


 We, BANK SARASIN & CO. LTD, Basel/Switzerland, for the
  account of Menderes Holding AG, Basel, hereby establish an unconditional and
  irrevocable standby letter of credit no. 5952, in favour of The Toronto Dominion
  Bank, 499 Granville Street & Pender, British Columbia, Canada. V6C 1V3,
  Transit#96990 004 for drawing up to 

USD 500,000. -- (US Dollars five hundred thousand) 

effective immediately and expiring at our office with our close
  of business on 

 30th September 2003 (thirtieth September two thousand and
  three) 

after which date this letter of credit shall become null and
  void. Except when the amount of this letter of credit is increased, this credit
  cannot be modified or revoked without your consent. 

 This letter of credit is established to secure a credit facility
  extended by The Toronto Dominion Bank, 499 Granville Street & Ponder, British
  Columbia, Canada V6C 1 V3 Transit#96990 004 to Response Biomedical Corp. 8855
  Northbrook Court, Burnaby, British Columbia, Canada VJ 5J1. 

 Credit is available to you by your authenticated swift demand
  stating: 

 "monies drawn pursuant to this letter of credit represents
  outstanding and unpaid principal and interest calculated up to the value date
  of the drawing due and owing in connection with an agreement between Response
  Biomedical Corp. 8855 Northbrook Court, Burnaby, British Columbia, Canada VJ
  5J1, and The Toronto Dominion Bank, 499 Granville Street & Pender, British
  Columbia, Canada V6C 1V3 Transit#96990 004." 

 Reimbursement shall be effected in accordance with your instructions
  contained in your authenticated swift demand. 

 Partial drawings are permitted. With each payment under this
  letter of credit our obligation will be reduced pro rata. 

 This letter of credit is subject to the uniform customs and
  practice for documentary credit (1993 revision) international chamber of commerce
  publication no. 500. 


Yours faithfully,



BANK SARASIN & CO. LTD. 


	/s/ Fabio Bobia	/s/ Linda Affolter
	Fabio Bobia	Linda Affolter


 Bank Sarasin & Cie AG . Elisabethensrrasse 62 - Postfach
  - CH-4002 Basel 

  Telefon +41 (0)61 277 77 77 • Telefax +41 (0)61 272 02 05 • Telex
  964 597 • Internet www.sarasin.ch