SECURITIES
      PURCHASE AGREEMENT

     

    THIS
      SECURITIES PURCHASE AGREEMENT
      (“Agreement”),
      dated
      as of December 12, 2007, is by and among Elizabeth Plaza ("Purchaser"),
      and
      each of the purchasers listed on Exhibit
      A
      attached
      hereto (collectively, the “Sellers”
      and
      individually, a “Seller”).

     

    WITNESSETH

     

    WHEREAS,
      Sellers
      are the owners of three year warrants to purchase shares of common stock, par
      value $0.0001 of Pharma-Bio Serv, Inc. a Delaware corporation (the “Company”).


     

    WHEREAS,
      Sellers
      desire to sell, transfer and assign to Purchaser warrants to purchase Four
      Hundred Sixty Six Thousand, Six Hundred and Sixty Seven (466,667) shares of
      common stock of the Company (the “Warrants”) in consideration for $0.77 per
      Warrant, as set forth on Schedule A attached hereto, which shall be payable
      by
      the issuance of a promissory note to each of the Sellers. 

     

    NOW
      THEREFORE,
      in
      consideration of the promises and respective mutual agreements herein contained,
      it is agreed by and between the parties hereto as follows:

     

    ARTICLE
      1

    SALE
      AND PURCHASE OF THE WARRANTS

     

    1.1    Sale
      of the Warrants.
      Upon
      the terms and conditions herein contained, at the Closing (as hereinafter
      defined), the Sellers, severally, each agrees to sell the Warrants to the
      Purchaser and the Purchaser hereby agrees to purchase the Warrants from each
      of
      the Sellers, free and clear of all liens, claims, pledges, mortgages,
      restrictions, obligations, security interests and encumbrances of any kind,
      nature and description.

     

    1.2    Consideration.
      The
      purchase price for the Warrants (the "Purchase Price") shall be $0.77 per
      warrant (an aggregate of Three Hundred Fifty Nine Thousand, Three Hundred and
      Thirty Three Dollars and Fifty Nine Cents ($359,333.59) for all of the Warrants)
      which shall be satisfied by the issuance at the time of closing of a Promissory
      Note (the “Note”) to each of the Sellers in the amounts set forth on Schedule A
      attached hereto. 

     

    ARTICLE
      2

    CLOSING

     

    2.1    Condition
      to Closing.
      The
      sole condition to the consummation of the transactions contemplated hereby
      shall
      be the Company’s obtaining a National Minority Supplier Development Council
      Minority-Controlled Certification (“Certification”) extending beyond December
      31, 2007. 

     

    2.2    Time
      and Place of Closing.
      The
      closing of the transactions contemplated by this Agreement (the "Closing")
      shall
      take place at the offices of Sichenzia Ross Friedman Ference LLP, 61 Broadway,
      New York, New York 10006 immediately after the Company receives the
      Certification (hereinafter the "Closing Date"). 

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    2.3    Delivery
      by Seller.
      At the
      Closing, each of the Sellers shall sell, assign, transfer, convey and deliver
      to
      the Purchaser warrant certificates representing the Warrants to be sold by
      such
      Seller free and clear of all liens, claims, charges, equities, encumbrances,
      restrictions and voting agreements of every kind. The warrant certificates
      shall
      be duly endorsed in blank. 

     

    2.4    Delivery
      by the Purchaser.
      At or
      prior to the Closing, the Purchaser shall deliver to each of the Sellers a
      Note
      in the principal amount of the purchase price for the Warrants purchased by
      the
      Purchaser from such Seller in the form of Exhibit B attached hereto.


     

    2.5    Delivery
      by the Company.
      The
      Purchaser shall cause the Company to issue and deliver new warrant certificates
      (the “New Warrants”) to the Purchaser in an amount equal to the number of
      Warrants purchased by her hereunder, and to a Seller, in the event that such
      Seller delivers a Warrant (pursuant to Section 2.2) to purchase shares of the
      Company’s common stock in excess of the number of Warrants sold by such Seller
      hereunder, in an amount equal to such excess. The New Warrants shall contain
      the
      same terms and conditions as the purchased Warrants. 

     

    ARTICLE
      3

    REPRESENTATIONS
      AND COVENANTS OF SELLERS

     

    Each
      Seller hereby represents and warrants to the Purchaser, severally but not
      jointly, and agrees that:

     

    3.1    Status
      of the Seller and the Warrants.
      Such
      Seller is the beneficial owner of the Warrants indicated next to his/its on
      Exhibit A attached hereto, and such Warrants are free and clear of all
      mortgages, pledges, restrictions, liens, charges, encumbrances, security
      interests, obligations or other claims.

     

    3.2    Authorization;
      Enforcement.
      (i)
      such Seller has all requisite power and authority to enter into and perform
      this
      Agreement and to consummate the transactions contemplated hereby and to sell
      the
      Warrants, in accordance with the terms hereof, (ii) in the case of a Seller
      which is not a natural person, the execution and delivery of this Agreement
      by
      such Seller and the consummation by it of the transactions contemplated hereby
      (including without limitation, the sale of the Warrants to the Purchaser) have
      been duly authorized by all necessary corporate, membership or partnership
      action on the part of the Seller and no further consent or authorization of
      such
      Seller is required, (iii) this Agreement has been duly executed and delivered
      by
      such Seller, and (iv) this Agreement constitutes a legal, valid and binding
      obligation of such Seller enforceable against such Seller in accordance with
      its
      terms, except as such enforceability may be limited by applicable bankruptcy,
      insolvency, reorganization, moratorium, liquidation or similar laws relating
      to,
      or affecting generally, the enforcement of creditors’ rights and remedies or by
      other equitable principles of general application

     

    3.3    No
      Conflicts.
      The
      execution, delivery and performance of this Agreement by such Seller and the
      consummation by such Seller of the transactions contemplated hereby (including,
      without limitation, the sale of the Warrants to the Purchaser) will not violate
      or conflict with, or result in a breach of any provision of, or constitute
      a
      default (or an event which with notice or lapse of time or both could become
      a
      default) under, or give to others any rights of termination, amendment,
      acceleration or cancellation of, any agreement, note, bond, indenture or other
      instrument to which such Seller is a party, or (iii) result in a violation
      of
      any law, rule, regulation, order, judgment or decree (including federal and
      state securities laws and regulations and regulations of any self-regulatory
      organizations to which such Seller is subject) applicable to such Seller. Such
      Seller is not required to obtain any consent, authorization or order of, or
      make
      any filing or registration with, any court, governmental agency, regulatory
      agency, self regulatory organization or stock market or any third party in
      order
      for it to execute, deliver or perform any of its obligations under this
      Agreement in accordance with the terms hereof. 

     

    
      
         

      

      
        2

        
          

        

      

      
         

      

    

     

    3.4    No
      Brokers.
      Such
      Seller has taken no action which would give rise to any claim by any person
      for
      brokerage commissions, finder’s fees or similar payments relating to this
      Agreement or the transactions contemplated hereby.

     

    ARTICLE
      4

    REPRESENTATIONS
      AND COVENANTS OF PURCHASER

     

    The
      Purchaser represents and warrants to Sellers as follows:

     

    4.1    Investment
      Representation.
      The
      Warrants are being acquired for investment for the Purchaser’s own account, not
      as a nominee or agent, and not with a view to the public resale or distribution
      thereof within the meaning of the Securities Act of 1933, as amended (the
“Securities Act”), without prejudice, however, to such Purchaser’s right at all
      times to sell or otherwise dispose of all or any part of such securities in
      compliance with applicable federal and state securities laws and as otherwise
      contemplated by this Agreement. 

     

    4.2    Suitability.
      The
      Purchaser understands that the purchase of the Warrants involves substantial
      risk. The Purchaser has experience as an investor in securities of companies
      and
      acknowledges that she can bear the economic risk of her investment in the
      Warrants and has such knowledge and experience in financial or business matters
      that she is capable of evaluating the merits and risks of this investment in
      the
      Warrants and protecting her own interests in connection with this
      investment.

     

    4.3    Accredited
      Investor.
      The
      Purchaser is an “accredited investor” within the meaning of Regulation D
      promulgated under the Securities Act.

     

    4.4    Transferability.
      The
      Purchaser understands that the Warrants have not been registered under the
      Securities Act and will not sell, offer to sell, assign, pledge, hypothecate
      or
      otherwise transfer any of the Warrants unless (i) pursuant to an effective
      registration statement under the Securities Act, (ii) such holder provides
      the
      Company with an opinion of counsel, in form and substance reasonably acceptable
      to the Company, to the effect that a sale, assignment or transfer of the
      Warrants may be made without registration under the Securities Act, (iii) such
      holder provides the Company with reasonable assurances (in the form of seller
      and broker representation letters) that the shares underlying the Warrants
      can
      be sold pursuant to Rule 144 promulgated under the Securities Act (“Rule
      144”)
      or (iv)
      pursuant to Rule 144(k) promulgated under the Securities Act following the
      applicable holding period. 

     

    4.5    Authorization;
      Enforcement.
      The
      Purchaser has all requisite power and authority to enter into and perform this
      Agreement and to consummate the transactions contemplated hereby and to issue
      the Notes to each of the Sellers, in accordance with the terms hereof and
      thereof, (ii) this Agreement and each of the Notes have been duly executed
      and
      delivered by the Purchaser, and (iii) this Agreement and each of the Notes
      constitute a legal, valid and binding obligation of the Purchaser enforceable
      against the Purchaser in accordance with its terms, except as such
      enforceability may be limited by applicable bankruptcy, insolvency,
      reorganization, moratorium, liquidation or similar laws relating to, or
      affecting generally, the enforcement of creditors’ rights and remedies or by
      other equitable principles of general application

     

    4.6    No
      Conflicts.
      The
      execution, delivery and performance of this Agreement by the Purchaser and
      the
      consummation by the Purchaser of the transactions contemplated hereby
      (including, without limitation, the issuance of the Notes to the Sellers) will
      not violate or conflict with, or result in a breach of any provision of, or
      constitute a default (or an event which with notice or lapse of time or both
      could become a default) under, or give to others any rights of termination,
      amendment, acceleration or cancellation of, any agreement, note, bond, indenture
      or other instrument to which the Purchaser is a party, or (iii) result in a
      violation of any law, rule, regulation, order, judgment or decree (including
      federal and state securities laws and regulations and regulations of any
      self-regulatory organizations to which the Purchaser is subject) applicable
      to
      the Purchaser. the Purchaser is not required to obtain any consent,
      authorization or order of, or make any filing or registration with, any court,
      governmental agency, regulatory agency, self regulatory organization or stock
      market or any third party in order for it to execute, deliver or perform any
      of
      its obligations under this Agreement in accordance with the terms hereof.


     

    4.7    No
      Brokers.
      The
      Purchaser has taken no action which would give rise to any claim by any person
      for brokerage commissions, finder’s fees or similar payments relating to this
      Agreement or the transactions contemplated hereby.

     

    
      
         

      

      
        3

        
          

        

      

      
         

      

    

     

    ARTICLE
      5

    MISCELLANEOUS

     

    5.1    Entire
      Agreement.
      This
      Agreement sets forth the entire agreement and understanding of the parties
      hereto with respect to the transactions contemplated hereby, and supersedes
      all
      prior agreements, arrangements and understandings related to the subject matter
      hereof. No understanding, promise, inducement, statement of intention,
      representation, warranty, covenant or condition, written or oral, express or
      implied, whether by statute or otherwise, has been made by any party hereto
      which is not embodied in this Agreement or the written statements, certificates,
      or other documents delivered pursuant hereto or in connection with the
      transactions contemplated hereby, and no party hereto shall be bound by or
      liable for any alleged understanding, promise, inducement, statement,
      representation, warranty, covenant or condition not so set forth.

     

    5.2    Notices.
      Any
      notice, request, instruction, or other document required by the terms of this
      Agreement, or deemed by any of the parties hereto to be desirable, to be given
      to any other party hereto shall be in writing and shall be given by facsimile,
      personal delivery, overnight delivery, or mailed by registered or certified
      mail, postage prepaid, with return receipt requested to the address or facsimile
      set forth on the signature page hereto. If notice is given by facsimile,
      personal delivery, or overnight delivery in accordance with the provisions
      of
      this Section, said notice shall be conclusively deemed given at the time of
      such
      delivery. If notice is given by mail in accordance with the provisions of this
      Section, such notice shall be conclusively deemed given seven days after deposit
      thereof in the United States mail. 

     

    5.3    Waiver
      and Amendment.
      Any
      term, provision, covenant, representation, warranty or condition of this
      Agreement may be waived, but only by a written instrument signed by the
      Purchaser and the Sellers. The failure or delay of any party at any time or
      times to require performance of any provision hereof or to exercise its rights
      with respect to any provision hereof shall in no manner operate as a waiver
      of
      or affect such party's right at a later time to enforce the same. No waiver
      by
      any party of any condition, or of the breach of any term, provision, covenant,
      representation or warranty contained in this Agreement, in any one or more
      instances, shall be deemed to be or construed as a further or continuing waiver
      of any such condition or breach or waiver of any other condition or of the
      breach of any other term, provision, covenant, representation or warranty.
      No
      modification or amendment of this Agreement shall be valid and binding unless
      it
      be in writing and signed by all parties hereto.

     

    5.4    Choice
      of Law.
      This
      Agreement and the rights of the parties hereunder shall be governed by and
      construed in accordance with the laws of the State of New York including all
      matters of construction, validity, performance, and enforcement and without
      giving effect to the principles of conflict of laws.

     

    5.5    Jurisdiction.
      The
      parties submit to the jurisdiction of the Courts of the County of New York,
      State of New York or a Federal Court empanelled in the State of New York for
      the
      resolution of all legal disputes arising under the terms of this Agreement,
      including, but not limited to, enforcement of any arbitration
      award.

     

    5.6    Counterparts.
      This
      Agreement may be executed in one or more counterparts, each of which shall
      be
      deemed an original, but all of which shall together constitute one and the
      same
      instrument. 

     

    5.7    Attorneys'
      Fees.
      If a
      dispute should arise between the parties hereunder or under any of the Notes
      including, but not limited to arbitration, the prevailing party shall be
      reimbursed by the non-prevailing party for all reasonable expenses incurred
      in
      resolving such dispute, including reasonable attorneys' fees exclusive of such
      amount of attorneys' fees as shall be a premium for result or for risk of loss
      under a contingency fee arrangement.

     

    5.8    Taxes.
      Any
      income taxes required to be paid in connection with the payments due hereunder,
      shall be borne by the party required to make such payment. Any withholding
      taxes
      in the nature of a tax on income shall be deducted from payments due, and the
      party required to withhold such tax shall furnish to the party receiving such
      payment all documentation necessary to prove the proper amount to withhold
      of
      such taxes and to prove payment to the tax authority of such required
      withholding.

     

    
      
         

      

      
        4

        
          

        

      

      
         

      

    


    IN
      WITNESS WHEREOF,
      the
      parties hereto have executed this Agreement, as of the date first written
      hereinabove.

     

    PURCHASER:

    


    /s/
      Elizabeth Plaza

    ELIZABETH
      PLAZA

    Suite
      110
      Mendez Vigo 373

    Dorado,
      PR 00646

    


    


    SELLERS:

    


    SAN
      JUAN
      HOLDINGS, INC. 

    


    


    By:/s/
      Addison M. Levi III

    Name:
      Addison M. Levi III

    Title:
      Principal

    MCS
      Plaza, Suite #305

    255
      Ponce
      de Leon Avenue

    San
      Juan,
      PR  00917

    


    


    /s/
      Nathan Renov

    NATHAN
      RENOV CUSTODIAN FOR AKIVA PERLYSKY

    2
      Lakeside Drive West

    Lawrence,
      NY 11550

    


    


    /s/
      Tova Katz

    TOVA
      KATZ
      CUSTODIAN FOR BENJI RENOV

    9
      Beechwood Drive

    Lawrence,
      NY 11559

    


    


    /s/
      Nathan Renov

    NATHAN
      RENOV CUSTODIAN FOR AVIGAIL PERLYSKY

    2
      Lakeside Drive West

    Lawrence,
      NY 11550

    


    


    /s/
      Jonathan Turkel

    JONATHAN
      TURKEL 

    44
      Wall
      Street, 2nd Floor

    New
      York,
      NY 10002

    


    


    /s/
      Leonard Katz

    LEONARD
      KATZ 

    44
      Wall
      Street, 2nd Floor

    New
      York,
      NY 10005

     

    
      
         

      

      
        5

        
          

        

      

      
         

      

    


    Exhibit
      A

     

    


    
      	
              NAME

            	
              NUMBER
                OF COMMON SHARES UNDERLYING WARRANT

            	
              WARRANT
                
CERTIFICATE NO.

            	
              PURCHASE
                PRICE

            
	
              San
                Juan Holdings, Inc. 

            	
              125,000

            	 	
              $96,250.00

            
	
              Nathan
                Renov custodian for Akiva Perlysky

            	
              69,870

            	 	
              $53,799.90

            
	
              Nathan
                Renov custodian for Avigail Perlysky

            	
              69,870

            	 	
              $53,799.90

            
	
              Tova
                Katz custodian for Benji Renov

            	
              139,739

            	 	
              $107,599.03

            
	
              Jonathan
                Turkel

            	
              31,094

            	 	
              $23,942.38

            
	
              Leonard
                Katz

            	
              31,094

            	 	
              $23,942.38

            
	
              TOTAL

            	
              466,667

            	 	
              $359,333.59

            


    

     

    
      
         

      

      
        6

        
          

        

      

      
         

      

    


    Exhibit
      B

     

    PROMISSORY
      NOTE

     

    
      	$___________	
              San
                Juan ,Puerto Rico

            
	 	
              December
                __,
                2007

            


    

    


    FOR
      VALUE
      RECEIVED, Elizabeth Plaza (the "Maker"), hereby promises to pay _________ (the
      "Holder"), the principal sum of _________________ ($_____) Dollars, in lawful
      money of the United States, on the same date she receives the payment due her
      on
      January 25, 2008 from Pharma Bio Serv Inc. (“PBSV”) pursuant to the agreement
      and plan of merger dated January 25, 2006 among Lawrence Consulting Group Inc.,
      PBSV, the Maker and Plaza Acquisition Corp. (the “Due Date”), Maker agrees to
      direct PBSV to immediately wire such portion of such payment as is necessary
      to
      repay in full this Note and all other like promissory notes issued on the date
      hereof by Maker pursuant to the Securities Purchase Agreement (“SPA”) dated the
      date hereof among Maker, Holder and the holders of all such other promissory
      notes in accordance with the wire instructions set forth in the
      SPA.

     

    This
      Note
      can be prepaid in whole or in part at any time without the consent of the
      Holder. 

     

    This
      Note
      shall bear interest at the maximum rate permitted by law per annum in the event
      the principal amount is not paid on the Due Date.

     

    The
      entire unpaid principal balance of this Note and interest accrued with respect
      thereto shall be immediately due and payable upon the occurrence of any of
      the
      following (each, an "Event of Default"):

     

    (a) Application
      for, or consent to, the appointment of a receiver, trustee or liquidator for
      Maker or of her property;

     

    (b) Admission
      in writing of the Maker's inability to pay her debts as they
      mature;

     

    (c) General
      assignment by the Maker for the benefit of creditors;

     

    (d) Filing
      by
      the Maker of a voluntary petition in bankruptcy or a petition or an answer
      seeking reorganization, or an arrangement with creditors; or

     

    (e) Entering
      against the Maker of a court order approving a petition filed against it under
      the federal bankruptcy laws, which order shall not have been vacated or set
      aside or otherwise terminated within 60 days.

     

    (f) Default
      in the payment of the principal or accrued interest on this Note, when and
      as
      the same shall become due and payable, whether on the Due Date, by acceleration
      or otherwise;

     

    
      
         

      

      
        7

        
          

        

      

      
         

      

    

     

    (g) Default
      in any covenant or obligation of Maker in favor of Holder arising pursuant
      to
      the SPA.

     

    All
      rights and remedies available to the Holder pursuant to the provisions of
      applicable law and otherwise are cumulative, not exclusive and enforceable
      alternatively, successively and/or concurrently after default by Maker pursuant
      to the provisions of this Note.

     

    This
      Note
      may not be changed, modified or terminated orally, but only by an agreement
      in
      writing, signed by the Holder and the Purchaser.

     

    This
      Note
      shall be governed by and construed in accordance with the laws of the State
      of
      New York and shall be binding upon the successors, endorsees or assigns of
      the
      Maker and inure to the benefit of the Holder, its successors, endorsees and
      assigns.

     

    The
      Maker
      hereby irrevocably consents to the jurisdiction of the courts of State of New
      York and the United States District Court for the Southern District of New
      York
      in connection with any action or proceeding arising out of or relating to this
      Note. If any term or provision of this Note shall be held invalid, illegal
      or
      unenforceable, the validity of all other terms and provisions hereof shall
      in no
      way be affected thereby.

     

    
      	 	
              ___________________________________

              Elizabeth Plaza

            


    

     

    
      
         

      

      
        8