November
      6, 2007

     

     

    Mr.
      Edward M. Chait

    2701
      Kent
      Avenue

    West
      Lafayette, IN 47906

     

    Dear
      Edward:

     

    The
      Board
      of Directors of Bioanalytical Systems, Inc. (the "Company")
      has
      approved the grant of non-qualified stock options to you. This letter will
      serve
      as notice of the grant, effective as of the date of this letter (the
      "Date
      of Grant"),
      and
subject
      to and conditioned in all respects on the approval of the shareholders of the
      Company,
      of
      an
      option to purchase (the "Option")
      45,000
      of the Common Shares of the Company (the "Option
      Shares")
      on the
      terms and conditions set forth herein, and upon your execution and delivery
      to
      the Company of the copy of this letter included herein will constitute our
      agreement as to those terms. This
      Option has not been granted under the terms of the Company’s employee stock
      option plans, and is not a "qualified" stock option as defined by the Internal
      Revenue Service.
      You are
      urged to consult with your tax advisors concerning the tax effect of the grant
      and exercise of this Option.

     

    1. OPTION
      PRICE.
      The
      purchase price of the Option Shares is $8.60 per share (the "Option
      Price").

     

    2. MEDIUM
      AND TIME OF PAYMENT.
      You
      must pay the Option Price with respect to the Option Shares being purchased
      at
      the time you exercise the Option. The Option Price may be paid either (a) in
      cash; (b) by certified check or by bank cashier's check; (c) if you can do
      so
      without violating Section 16(b) of the Securities Exchange Act of 1934, through
      the tender to the Company of outstanding Common Shares, which shall be valued,
      for purposes of determining the extent to which the purchase price has been
      paid, at the fair market value of the Common Shares on the date of exercise
      of
      the Option; (d)
      by
surrendering
      a sufficient portion of the vested Option based on the difference between the
      exercise price of the Option and the fair market value at the time of exercise
      of the Shares subject to the Option,
      or (e)
      by any combination of (a), (b), (c) and (d).

     

    3. TERM
      AND EXERCISABILITY OF OPTIONS.
      The
      Option is effective immediately upon your acceptance of this letter subject
      only
      to approval of the Company's shareholders. Unless the Option is terminated
      or
      vesting of the Option or any portion thereof is accelerated (in each case as
      provided in this letter), the Option shall vest and become exercisable in three
      equal installments on November 30, 2008, 2009 and 2010. The Option shall also
      vest and become exercisable as to all unvested Option Shares upon the occurrence
      of a "Change in Control" as defined in your Employment Agreement with the
      Company of even date herewith, as the same may be amended from time to time.
      The
      Option will be considered to have been effectively exercised only upon delivery
      to the Company, with a copy to the Chair of the Compensation Committee of the
      Board of Directors of the Company, of the Option Price and a "Notice
      of Exercise"
      in the
      form attached hereto, and the satisfaction of all other conditions described
      in
      this letter. The Option shall expire as to all unexercised Option Shares at
      the
      close of business on the tenth anniversary of the date of this letter (or on
      the
      next business day if that date is a Saturday, Sunday or holiday).

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    Mr.
      Edward M. Chait

    November
      6, 2007

    Page
      2

     

    4. APPROVAL
      BY SHAREHOLDERS.
      The
      Option granted hereby is conditioned upon and subject to approval by the
      shareholders of the Company. In the event that the shareholders of the Company
      fail to approve the grant of the Option within twelve (12) months of the date
      of
      this letter, the Option shall be null and void and of no effect, and neither
      you
      nor the Company shall have any continuing rights or obligations hereunder.
      The
      Company will submit the Option to its shareholders for approval at the first
      annual or special meeting of its shareholders occurring after the date hereof,
      and in any event prior to the expiration of twelve (12) months from the date
      hereof.

     

    5. CESSATION
      OF SERVICE WITH THE COMPANY.
      In the
      event you cease to serve as an employee of the Company or any of its
      subsidiaries, this Option shall terminate 30 days after your termination of
      employment as to any unexercised Option Shares; provided, however, that if
      termination of employment is due to retirement with the consent of the Company,
      the expiration of the term of your employment with the Company set forth in
      your
      employment agreement, or is due to a permanent and total disability, you shall
      have the right to exercise the Option with respect to the Common Shares for
      which it could have been exercised on the effective date of termination of
      employment at any time within three (3) months after the termination date.
      In
      the event of your death while serving as an employee of the Company or any
      of
      its subsidiaries, your personal representative shall have the right to exercise
      this Option with respect to the Common Shares for which it could have been
      exercised on the date of your death at any time within six (6) months of your
      death. Whether termination is a retirement with the consent of the Company
      or
      due to permanent and total disability, and whether an authorized leave of
      absence on military or government service shall be deemed to constitute
      termination of employment for the purposes of this Option, shall be determined
      by the Board of Directors in its sole discretion, which determination shall
      be
      final and conclusive.

     

    6. RECAPITALIZATION.
      The
      number of Option Shares and the Option Price each shall be proportionally
      adjusted for any increase or decrease in the number of issued Common Shares
      resulting from a subdivision or consolidation of shares of the Company, the
      payment of a share dividend, a share split or other increase or decrease in
      the
      outstanding Common Shares effected without receipt of consideration by the
      Company (including an increase or decrease effected as a part of the
      Recapitalization of the Company, as defined herein). In the event that there
      shall be a recapitalization or reorganization of the Company or a
      reclassification of its outstanding shares (each a "Recapitalization")
      as a
      result of which other shares (the "New
      Shares")
      are
      issued in exchange for Common Shares, then there shall be substituted for the
      Option Shares then issuable hereunder that number of New Shares into which
      those
      Option Shares have been converted had they been outstanding at the effective
      date of the Recapitalization.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    Mr.
      Edward M. Chait

    November
      6, 2007

    Page
      3

     

    7. MERGER,
      DISSOLUTION.
      If the
      Company shall enter into any agreement of merger or consolidation (whether
      or
      not it shall be the surviving entity thereunder), the Company shall have the
      right to terminate this Option as of any date specified in a written notice
      given to you not less than 30 days prior to the termination date. If the merger
      or consolidation described in that notice is not consummated within 180 days
      following the termination date of this Option specified in the notice, this
      Option thereafter shall be deemed to have been continuously in effect since
      the
      date hereof. In the event of the sale of all or substantially all of the assets
      of the Company and the distribution of the proceeds thereof to shareholders
      in
      liquidation of the company, the Company shall give you 30 days prior written
      notice specifying record date for the purpose of determining the shareholders
      entitled to participate in that distribution and this Option shall expire as
      to
      all Option Shares that remain unexercised as of the date of that
      distribution.

     

    8. NONASSIGNABILITY.
      This
      Option is not assignable or transferable except by will or under the laws of
      descent and distribution. During your lifetime, this Option shall be exercisable
      only by you (or if you become incapacitated, by your legal guardian or
      attorney-in-fact).

     

    9. ISSUANCE
      OF SHARES AND COMPLIANCE WITH SECURITIES LAWS.
      The
      Company may postpone the issuance and delivery of certificates representing
      Common Shares until (a) the admission of such shares to listing on any exchange
      on which shares of the Company of the same class are then listed and (b) the
      completion of any requirements for registration or other qualification of the
      shares under any state or Federal law, rule or regulation or the rules and
      regulations of any exchange upon which the Common shares are traded as the
      Company shall determine to be necessary or advisable. The Company shall use
      its
      reasonable commercial efforts to complete any required registration or other
      qualification. You have no right to require the Company to register the Common
      Shares acquired upon the exercise of this Option under federal or state
      securities laws. As a condition to the effective exercise of this Option you
      may
      be required to make such representations and furnish such information as may,
      in
      the opinion of counsel for the Company, be appropriate to permit the Company
      to
      determine whether registration or qualification of those shares is required
      in
      connection with that transaction.

     

    10. RIGHTS
      AS A SHAREHOLDER.
      You
      shall have no rights as a shareholder with respect to Common Shares subject
      to
      this Option until the date of issuance of a certificate to you. A certificate
      will not be issued until you have exercised the Option, fully paid for the
      Common Shares acquired thereby and satisfied all other details described in
      this
      letter. No adjustment will be made for dividends or other rights for which
      the
      record date is prior to the date a certificate is issued.

     

    11. NO
      OBLIGATION TO EXERCISE OPTION.
      The
      grant of this Option imposes no obligation upon you to exercise the
      Option.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    Mr.
      Edward M. Chait

    November
      6, 2007

    Page
      4

     

    12. NO
      OBLIGATION TO CONTINUE EMPLOYMENT.
      The
      grant of this Option to you does not constitute any contract of employment
      between you and the Company, and does not impose any obligation of the Company
      to continue your employment.

     

    13. WITHHOLDINGS.
      As a
      condition to the effective exercise of this Option, the Company shall have
      the
      right to require you to remit to the Company amounts sufficient to satisfy
      any
      applicable withholding requirements set forth in the Internal Revenue Code
      of
      1986, as amended, or under state or local law relating to the Option. The
      Company shall have the right, to the extent permitted by law, to deduct from
      any
      payment of any kind otherwise due to you any federal, state or local taxes
      of
      any kind required by law to be withheld with respect to the exercise of the
      Option.

     

    14. POWER
      AND AUTHORITY.
      The
      Board of Directors shall have the full power and authority to take all actions
      and make all determinations required or provided for under the terms of this
      Option; to interpret and construe the provisions of this letter, which
      interpretation or construction shall be final, conclusive and binding on the
      Company and you; and to take any and all other actions and make any and all
      other determinations not consistent with the specific terms and provisions
      of
      this letter which the Board of Directors deems necessary or
      appropriate.

     

    Please
      acknowledge your receipt of this letter and your agreement to the terms set
      forth herein by signing and returning the copy enclosed for that
      purpose.

     

    
      	 	
              Very
                truly yours,

            
	 	 
	 	
              BIOANALYTICAL
                SYSTEMS, INC.

            
	 	 
	 	 
	 	
              By:

            	
              /s/
                Richard M. Shepperd

            
	 	 	
              Richard
                M. Shepperd, President

            
	 	 
	 	
              Accepted
                and agreed to:

            
	 	 
	 	
              
                /s/
                  Edward M. Chait

              

            
	 	
              Edward
                M. Chait

            
	 	 
	 	
              Date:

            	
              
                November
                  6, 2007

              

            


    

    


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    EXHIBIT
      A

     

    BIOANALYTICAL
      SYSTEMS, INC.

     

    NOTICE
      OF EXERCISE

     

    Date:
      __________

     

    Mr.
      Michael R. Cox

    Chief
      Financial Officer

    BIOANALYTICAL
      SYSTEMS, INC.

    2701
      Kent
      Avenue

    West
      Lafayette, Indiana 47906

     

    Dear
      Mr.
      Cox:

     

    Pursuant
      to the agreement dated May 18, 2007 granting me an option ("Option")
      with
      respect to the purchase of Common Shares of Bioanalytical Systems, Inc.,
      please accept this letter as notice of exercise of the Option with respect
      to
      ___________ Common Shares. I am tendering full payment to the Company for the
      Common Shares and all applicable withholdings in one or more of the following
      forms:

     

    1. Cash
      in
      the amount of $  .

     

    2. Certified
      or bank cashier's check in the amount of $   .

     

    3. Tender
      to
      the Company of   
      outstanding Common Shares.

     

    4. Surrender
      of vested Options to purchase  Common
      Shares that are subject to the Option.

     

    Unless
      I
      have delivered herewith sufficient funds to pay in full all required
      withholdings under applicable law, I authorize the Company to withhold from
      the
      Common Shares otherwise issuable to me as a result of this exercise of the
      Option to pay in full all such required withholdings.

     

    
      	 	
               

            
	 	
              Signature

            
	 	 
	 	 
	 	
               

            
	 	
              Printed
                Name

            
	 	 
	 	
               

            
	 	 
	 	
               

            
	 	
              Address

            


    

     

    Cc:
      Compensation Committee Chairman