**Exhibit4.1**
| **COMMON STOCK** |   |   |   | **COMMON  STOCK** |
|------------------|--------|--------|--------|-------------------|
|             |   |   |   |              |
| PAR VALUE $0.02  |   |   |   |              |

** **
|                 | ** ** | **Cyanotech**                                       | ** ** | ** ** |
|-----------------|------------|-----------------------------------------------------|------------|------------|
| **Certificate** | ** ** | ** **                                          | ** ** | **Shares** |
| **Number**      |       | **CYANOTECH  CORPORATION**                          |       | ** ** |
|            |       | INCORPORATED  UNDER THE LAWS OF THE STATE OF NEVADA |       |       |
|            |       | 7,500,000  AUTHORIZED SHARES $0.02 PAR VALUE        |       |       |

 
| THIS CERTIFIES THAT |   |   |   | CUSIP 232437 30  1                   |
|---------------------|--------|--------|--------|--------------------------------------|
|                |   |   |   | SEE REVERSE FOR  CERTAIN DEFINITIONS |

 

is the owner of

FULLY-PAID ANDNON-ASSESSABLE SHARES OF THE COMMON STOCK OF

**Cyanotech Corporation(hereinafter called the “Company”)**, transferable on the booksof the Company in person or by duly authorized attorney, upon surrender of thisCertificate properly endorsed. This Certificate and the shares representedhereby, are issued and shall be held subject to all of the provisions of theArticles of Incorporation, as amended, and the By-Laws, as amended, of theCompany (copies of which are on file with the Company and with the TransferAgent), to all of which each holder, by acceptance hereof, assents. ThisCertificate is not valid unless countersigned and registered by the TransferAgent and Registrar.

**Witness** the facsimileseal of the Company and the facsimile signatures of its duly authorizedofficers.
|                                       |                          |                       | DATED 06/22/2007 |
|---------------------------------------|-------------------------------|-----------------------|------------------|
|                                  |
| COUNTERSIGNED AND REGISTERED          |
| **COMPUTERSHARE TRUST COMPANY, N.A.** |
| President                             | (DENVER)                      |
|                                  | TRANSFER AGENT AND REGISTRAR, |
|                                       | By                            |                       |
| Secretary                             |
|                                  |                          | AUTHORIZED  SIGNATURE |

 

**SECURITYINSTRUCTIONS ON REVERSE**

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**CYANOTECHCORPORATION**

The followingabbreviations, when used in the inscription on the face of this certificate,shall be construed as though they were written out in full according toapplicable laws or regulations:
| TEN COM | - as tenants in common                                                            | UNIF GIFT MIN ACT- |                                    Custodian |
|---------|-----------------------------------------------------------------------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|    |                                                                              |               | (Cust)                                                                                                                                                                                                                      | (Minor) |
| TEN ENT | - as tenants by the entireties                                                    |               | under Uniform Gifts to Minors Act                                                                                                                                                                                           |   |
|    |                                                                              |               |                                                                                                                                                                                                                        |          (State) |
| JT TEN  | - as joint  tenants with right of survivorship  and not as tenants in common | UNIF TRF MIN ACT   |    Custodian  (until age      )                                                                                                                                                |
|    |                                                                              | (Cust)             |       (Minor)                                                                                                                                                                                 |
|    |                                                                              |               | under Uniform Transfers to Minors Act                                                                                                                                                                                       |   |
|    |                                                                              |               |                                                                                                                                                                                                                        |        (State) |
|    | Additional abbreviations may also be used though not  in the above list.          |
|         |                                                                                   |                    |                                                                                                                                                                                                                             |  |  |  |  |

 

THE COMPANY WILL FURNISHWITHOUT CHARGE TO EACH SHAREHOLDER WHO SO REQUESTS, A SUMMARY OF THE POWERS,DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL OR OTHERSPECIAL RIGHTS OF EACH CLASS OF STOCK OF THE COMPANY AND THE QUALIFICATIONS,LIMITATIONS OR RESTRICTIONS OF SUCH PREFERENCES AND RIGHTS, AND THE VARIATIONSIN RIGHTS, PREFERENCES AND LIMITATIONS DETERMINED FOR EACH SERIES, WHICH AREFIXED BY THE ARTICLES OF INCORPORATION OF THE COMPANY, AS AMENDED, AND THERESOLUTIONS OF THE BOARD OF DIRECTORS OF THE COMPANY, AND THE AUTHORITY OF THEBOARD OF DIRECTORS TO DETERMINE VARIATIONS FOR FUTURE SERIES. SUCH REQUEST MAYBE MADE TO THE OFFICE OF THE SECRETARY OF THE COMPANY OR TO THE TRANSFER AGENT.THE BOARD OF DIRECTORS MAY REQUIRE THE OWNER OF A LOST OR DESTROYED STOCKCERTIFICATE, OR HIS LEGAL REPRESENTATIVES, TO GIVE THE COMPANY A BOND TOINDEMNIFY IT AND ITS TRANSFER AGENTS AND REGISTRARS AGAINST ANY CLAIM THAT MAYBE MADE AGAINST THEM ON ACCOUNT OF THE ALLEGED LOSS OR DESTRUCTION OF ANY SUCHCERTIFICATE.
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                   | PLEASE INSERT SOCIAL  SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------|
| For value received,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | hereby sell, assign and  transfer unto                                                                 |                                                                   |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |
| (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS,  INCLUDING POSTAL ZIP CODE, OF ASSIGNEE)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   | 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 in the premises.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Signature(s)  Guaranteed: Medallion Guarantee Stamp                                                    |
| Dated:                                                                        20                              | THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR                                         |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | INSTITUTION (Banks, Stockholders, Savings and Loan Associations  and Credit Unions)                    |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE  MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |
| Signature:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                   |                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |
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|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |
| Signature:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                   |                                                                   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Notice:                                                                                                | The signature to this assignment must correspond with  the name        |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   | as written upon the face of the certificate, in every  particular,     |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   | without alteration or enlargement, or any change  whatever.            |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                   |                                                                   |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                        |                                                                        |  |  |  |  |  |  |

 

**SECURITY INSTRUCTIONS**

THIS IS WATERMARKED PAPER.DO NOT ACCEPT WITHOUT NOTINGWATERMARK. HOLD TO LIGHT TO VERIFY WATERMARK.

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