REPLACEMENT
PROMISSORY NOTE

    


    
      
        
          	
                  $3,000,000.00

                	
                  Dated:
      July _____, 2009

                
	 
      	
                  Indianapolis,
      Indiana

                


        

      

    

    


    FOR VALUE RECEIVED, the undersigned
BIOANALYTICAL SYSTEMS, INC., an Indiana corporation (the “Borrower”), hereby promises to
pay to the order of NATIONAL CITY BANK, as successor by merger to National City
Bank of Indiana (“Bank”), or its assigns, at its
principal office at Indianapolis, Indiana, or at such other place as the holder
hereof may designate in writing, in lawful money of the United States of America
and in immediately available funds, the principal sum of Three Million Dollars
($3,000,000.00), or so much thereof as may be advanced and outstanding from time
to time, together with interest on the unpaid principal balance existing from
time to time at the per annum rates and on the dates set forth in the Agreement
(hereinafter defined).  The entire unpaid balance of principal, and
all accrued and unpaid interest thereon, shall be due and payable on the Line of
Credit Maturity Date, and Borrower shall make such mandatory principal payments
as are required to be made under the terms of Section 2.3 of the
Agreement.

    


    Bank shall, and is hereby authorized
to, record in accordance with its usual practice, the date and amount of each
advance and each principal payment hereunder.

    


    This Note is issued pursuant to, is
entitled to the benefit of, and is subject to the provisions of that certain
Amended and Restated Credit Agreement between Borrower and Bank dated as of
January 4, 2005, as amended January 16, 2007, as further amended October 24,
2007, as further amended January 16, 2009, and as further amended of even date
herewith (as amended, and as the same may be further amended from time to time
(the “Agreement”).  Advances
under this Note shall be made in accordance with the Agreement.  The
Agreement, among other things, contains a description of the collateral securing
this Note, the definitions of the proper nouns used herein and provisions for
acceleration of the maturity hereof upon the happening of certain stated
events.

    


    Subject to the terms of the Agreement,
Borrower may borrow, repay, reborrow and repay the principal amount of this Note
at any time and from time to time.

    


    If Borrower fails to make the payment
of any installment of principal or interest, as provided in the Agreement, when
due, or upon the occurrence of any other Default, then in any of such events, or
at any time thereafter prior to such Default being cured, the entire principal
balance of this Note, and all accrued and unpaid interest thereon, irrespective
of the maturity date specified herein, together with reasonable attorneys’ fees
and other costs incurred in collecting or enforcing payment or performance
hereof and with interest from the date of Default on the unpaid principal
balance hereof at the Default rate specified in the Agreement, shall, at the
election of the holder hereof (except as otherwise provided for automatic
acceleration on the occurrence of certain Defaults specified in the Agreement),
and without relief from valuation and appraisement laws, become immediately due
and payable.

     

      
        

      

    

    
      
        
          	
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      PROMISSORY NOTE

                	
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    If any payment is not received by Bank
within ten (10) days after its due date, Bank may assess and Borrower agrees to
pay a late fee equal to the greater of: (a) five percent (5%) of the past due
amount, or (b) Twenty Dollars ($20.00).  This late fee shall be in
addition to, and not in lieu of, any other remedy Bank may have and is in
addition to any reasonable fees and charges of any attorneys which Bank is
entitled to employ, whether authorized herein or by law.

    


    Borrower and all endorsers, guarantors,
sureties, accommodation parties hereof and all other parties liable or to become
liable for all or any part of this indebtedness, severally waive demand,
presentment for payment, notice of dishonor, protest and notice of protest and
expressly agree that this Note and any payment coming due under it may be
extended or otherwise modified from time to time without in any way affecting
their liability hereunder.

    


    This Note completely replaces that
certain Replacement Promissory Note dated October 24, 2007 from Borrower to Bank
in the face amount of $5,000,000 (the "Replacement Promissory Note"),
and continues to evidence the indebtedness evidenced by such Replacement
Promissory Note.  Bank shall mark the Replacement Promissory Note
“replaced” and return the Replacement Promissory Note to Borrower promptly upon
Borrower's execution and delivery to Bank of this Note  to
Bank.

    


    This Note shall be construed according
to and governed by the laws of the State of Indiana.  Notice of
acceptance of this Note is hereby waived by Borrower.

    


    Any action, claim, counterclaim,
cross-claim, proceeding, or suit, whether at law or in equity, whether sounding
in tort, contract, or otherwise at any time arising under or in connection with
this Note or any other Loan Document, the administration, enforcement, or
negotiation of this Note or any other Loan Document, or the performance of any
obligation in respect of this Note or any other Loan Document (each such action,
claim, counterclaim, cross-claim, proceeding, or suit, an “Action”) may be brought in any
federal or state court located in Marion County, Indiana.  Borrower
hereby unconditionally submits to the jurisdiction of any such court with
respect to each such Action and hereby waives any objection Borrower may now or
hereafter have to the venue of any such Action brought in any such
court.  BORROWER HEREBY, AND EACH HOLDER OF THIS NOTE, BY TAKING
POSSESSION HEREBY, KNOWINGLY AND VOLUNTARILY WAIVES JURY TRIAL IN RESPECT OF ANY
ACTION.

    


    [signatures
on following pages]

     

    
      

    

    
      
        
          	
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      PROMISSORY NOTE

                	
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    IN
WITNESS WHEREOF, Borrower has caused this Note to be executed by its duly
authorized officer as of the day and year first hereinabove
written.

    


    
      
        
          
            
              
                
                  	
                          BIOANALYTICAL
      SYSTEMS, INC.

                        
	 
      	 
	
                          By:

                        	 


                

              

            

          

        

      

    

    
      
        
          
            
              
                
                  
                    	
                            Printed:

                          	 


                  

                

              

            

          

        

      

      
        
          
            
              
                
                  
                    	
                            Its:

                          	 


                  

                

              

            

          

        

      

    

    


    
      
        
          	
                  STATE OF INDIANA

                	
                  )

                
	 
      	
                  )SS:

                
	
                  COUNTY OF ____________  

                	
                  )

                


        

      

    

    


    Personally appeared before me, a Notary
Public in and for said County and State, _________________________,
____________________ of said corporation, known to me as the person named
herein, who after being duly sworn upon his oath, stated to me that he has been
duly authorized and empowered to execute the foregoing Agreement on behalf of
said corporation.

    


    In Witness Whereof, I have hereunto set
my hand and Notarial Seal, this _______ day of July, 2009.

    


    
      
        
          
            
              
                	
                        My
      Commission Expires:

                      	 
      	 
      	 
      
	 
      	 
      	 
      	
                        Notary

                      	 
      
	
                        My
      County of Residence:

                      	 
      	 
      	 
      
	 
      	 
      	 
      	
                        Printed

                      	 
      


              

            

          

        

      

    

     

    
      

    

    
      
        
          	
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