Specimen Stock Certificate.



 Exhibit 4.2 
  

													
		 	 COMMON STOCK
  
	  		  		  		 	 COMMON STOCK
  
	 	
		 	  
 Number
 ---
  
	  		  	CERUS	  		 	  
 Shares
 ***0***
  
	 	
			
	 INCORPORATED UNDER THE LAWS        

OF THE STATE OF DELAWARE        
	  		  	SEE REVERSE FOR CERTAIN DEFINITIONS AND A STATEMENT AS TO THE POWERS, DESIGNATIONS, PREFERENCES, RESTRICTIONS, AND RIGHTS OF SHARES

							
		 		  		  		  		 	CUSIP  157085  10  1	 	

  

							
	THIS CERTIFIES THAT	 		    	  
 SPECIMEN
  
	  	
				
		 		    		  	
	IS THE RECORD OWNER OF	 		    	  
 ZERO
  
	  	

 FULLY PAID AND NON-ASSESSABLE SHARES OF COMMON SHARES, $0.001 PAR VALUE OF 

----------------------CERUS CORPORATION---------------------- 
 transferable on the books of the Corporation by the registered holder hereof in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid
unless countersigned by the Transfer Agent and registered by the Registrar. 
 In Witness Whereof the Corporation has caused this certificate to
be signed in facsimile by it authorized officers and its facsimile seal to be affixed. 
  

									
	Dated	 		  		 		  	
		 	 		
	 /s/ Lori L. Roll
	 	 	  	CERUS CORPORATION	 		  	 /s/ Claes Glassell

	Secretary	 	 	  	 	 		  	President and
		 	 	  	 CORPORATE SEAL
  
	 		  	Chief Executive Officer
		 	 	  	 	 		  	

  

							
		 	  
 COUNTERSIGNED AND REGISTERED:
 WELLS FARGO BANK, N.A.

		 
		 	TRANSFER AGENT AND REGISTRAR,
		 
		 	               VOID
		 	By	  	  
	  	 
		 	 	  	 AUTHORIZED SIGNATURE
  
	  	 








 CERUS CORPORATION 
 The Corporation is authorized to issued Common Stock and Preferred Stock. The Board of Directors of the Company has the authority to fix the
number of shares and the designations of Preferred Stock and to determine or amend the preferences, privileges, and restrictions granted to or imposed upon any unissued shares of Preferred Stock. 
 The Corporation shall furnish without charge to each stockholder who so requests a statement of the powers, designations, preferences and
relative, participating, optional or other special rights of each class of stock of the Corporation or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights so far as the same shall have been fixed, and
of the authority of the Board of Directors to designate and fix any preferences, rights and limitations of any wholly unissued series. Such requests shall be made to the Corporation’s Secretary at the principal office of the Corporation.

  

											
	  
 The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:



											
	 	 		 	UNIF GIFT MIN ACT –
                       Custodian
                            
	TEN COM	 	as tenants in common	 		 	(Cust)                          
(Minor)            
	 		 
	TEN ENT	 	as tenants by entireties	 	                            under Uniform Gifts to Minors Act
                                    
	 	 		 		 		 		 	(State)                    
	JT TEN	 	as joint tenants with right of	 	UNIF TRF MIN ACT –                      Custodian (until age    
           )
	 	 	survivorship and not as	 	(Cust)                                       
               
	 	 	tenants in common	 	                                 under Uniform Transfers

	 	 		 		 	(Minor)                  	 	 
	 	 		 		 	to Minors Act
                                        
          
	 	 		 		 		 	                (State)
	 Additional abbreviations may also be used though not in the above list.
  


 For value received,
                                         
                                         
                               hereby sell, assign and transfer unto 
 PLEASE INSERT SOCIAL SECURITY OR OTHER 
     IDENTIFYING NUMBER OF ASSIGNEE 
  

			
	 	
	 	  	

  
  
  
  
 (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS OF ASSIGNEE) 
  
  
  
  
  

			
	 	 	Shares

  

			
	of the capital stock represented by the within Certificate, and do hereby irrevocably constitute and appoint	 	 

  

			
	 	 	Attorney to

 transfer the said stock on the books of the within named Corporation with full power of substitution.

 Dated:                     

  

					
		 	X	  	  

			
		 	X	  	  

		 	NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME(S) AS WRITTEN UPON THE FACE OF THE CERTIFICATE, IN EVERY PARTICULAR WITHOUT ALTERATION OR
ENLARGEMENT OR ANY CHANGE WHATSOEVER.

 
  

			
	SIGNATURE(S) GUARANTEED	  	  

		  	THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED
SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.

  

	
	This certificate also evidences and entitles the holder hereof to certain rights as set forth
in a Rights Agreement between Cerus Corporation (the “Company”) and Wells Fargo Bank, N.A. (as successor to Wells Fargo Bank Minnesota, N.A., formerly known as Norwest Bank Minnesota, N.A.) as Rights Agent (the “Rights Agent”),
dated as of November 3, 1999 and amended as of August 6, 2001, as further amended from time to time (the “Rights Agreement”), the terms of which are herby incorporated herein by reference and a copy of which is on file at the
principal executive offices of the Company. Under certain circumstances, as set forth in the Rights Agreement, such Rights will be evidenced by separate certificates and will no longer be evidenced by this certificate. The Company will mail to the
holder of this certificate a copy of the Rights Agreement without charge after receipt of a written request therefor. As described in the Rights Agreement, Rights issued to any person who becomes an Acquiring Person or an Affiliate or Associate
thereof (as defined in the Rights Agreement) and certain related persons, whether currently held by or on behalf of such Person or by any subsequent holder, shall become null and void.

 KEEP THIS CERTIFICATE IN A SAFE PLACE. IF IT IS LOST, STOLEN, OR DESTROYED, THE
CORPORATION MAY REQUIRE A BOND OF INDEMNITY AS A CONDITION TO THE ISSUANCE OF A REPLACEMENT CERTIFICATE