**UNITED STATESSECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

 

**Form 10-Q/A**

 

**(Mark One)**

** **
| **x** | **QUARTERLY  REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE  ACT OF 1934** |
|-------|--------------------------------------------------------------------------------------------------------------|

** **

**Forthe quarterly period ended September 30, 2009**

** **

**OR**

** **
| **o** | **TRANSITION  REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE  ACT OF 1934** |
|-------|---------------------------------------------------------------------------------------------------------------|

 

**Commission File Number 001-33484**

 

**HELICOS BIOSCIENCES CORPORATION**

(Exact name of registrant as specified in its charter)

 

| **Delaware**  (State or other jurisdiction of  incorporation or organization) | ** ** | **05-0587367**(I.R.S.  Employer  Identification No.) |
|-------------------------------------------------------------------------------|------------|------------------------------------------------------|

 

**OneKendall Square, Building 700, Cambridge, MA 02139(617) 264-1800**(Address,including zip code, and telephone number, includingarea code, of registrant’s principal executive offices)

 

Indicateby check mark whether the registrant (1) has filed all reports required tobe filed by Section 13 or 15(d) of the Securities Exchange Act of1934 during the preceding 12 months (or for such shorter period than theregistrant was required to file such reports), and (2) has been subject tosuch filing requirements for the past 90 days. Yes: x  No: o

 

Indicateby check mark whether the registrant has submitted electronically and posted onits corporate website, if any, every Interactive Data File required to besubmitted and posted pursuant to Rule 405 of Regulation S-T (Section 232.405of this chapter) during the preceding 12 months (or for such shorterperiod that the registrant was required to submit and post such files). Yes: o  No: o

 

Indicateby check mark whether the registrant is a large accelerated filer, anaccelerated filer, a non-accelerated filer or a smaller reporting company. Seethe definitions of “large accelerated filer,” “large accelerated filer” and “smallerreporting company” in Rule 12b-2 of the Exchange Act. (Check one):

 

| Large accelerated filer o                                       |   | Accelerated filer o              |
|--------------------------------------------------------------------------------|--------|--------------------------------------------|
|                                                                           |   |                                       |
| Non-accelerated filer o(Do not check if a smaller reporting company) |   | Smaller reporting company x |

 

Indicateby check mark whether the registrant is a shell company (as defined in Rule 12b-2of the Exchange Act). Yes: o  No: x

 

Thenumber of shares of the registrant’s Common Stock, $.001 par value, outstandingas of October 31, 2009, was 72,963,658 shares.

 

 

 

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**EXPLANATORY NOTE**

 

This Form 10-Q/Aconstitutes Amendment No. 1 to the Quarterly Report on Form 10-Q ofHelicos BioSciences Corporation for the period ended September 30, 2009,originally filed with the Securities and Exchange Commission on November 9,2009 (the “Original Filing”). We are filing this Amendment No. 1 to ourQuarterly Report on Form 10-Q solely for the purpose of correcting certaintypographical errors contained in Exhibit 31.1 and Exhibit 31.2 inthe Original Filing. This Amendment No. 1 does not change any otherportion of the Original Filing.  ThisAmendment No. 1 speaks as of the original filing date of the OriginalFiling and does not reflect events occurring after the filing date of theOriginal Filing, or modify or update the disclosures therein in any way otherthan as required to reflect the amendment described above.

 

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**SIGNATURES**

 

Pursuantto the requirements of the Securities Exchange Act of 1934, the registrant hasduly caused this report to be signed on its behalf by the undersigned thereuntoduly authorized.

 

 
|                             | HELICOS BIOSCIENCES  CORPORATION                                                                                                                   |
|----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------|
|                             |                                                                                                                                               |
|                             |                                                                                                                                               |
|  Dated: March 31, 2010 |                                                                                                                                               |
|                             | /s/ Ronald A.  Lowy                                                                                                                                |
|                             | Ronald A. Lowy *President and Chief Executive Officer   (Principal Executive Officer)*                                                             |
|                             |                                                                                                                                               |
|  Dated: March 31, 2010 |                                                                                                                                               |
|                             | /s/ Jeffrey R. Moore                                                                                                                               |
|                             | Jeffrey R. Moore  *Senior Vice President, Chief Financial  Officer and Treasurer   (Principal Financial Officer and Principal Accounting Officer)* |

** **

** **

**EXHIBIT INDEX**

 
| 31.1   |   | Certification pursuant  to Section 302 of the Sarbanes-Oxley Act of 2002 |
|--------|--------|-------------------------------------------------------------------------------|
|   |   |                                                                          |
| 31.2   |   | Certification pursuant  to Section 302 of the Sarbanes-Oxley Act of 2002 |

 

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