Exhibit 10.50

AMENDMENT TO SECURITIES PURCHASE AGREEMENT

This Amendment to Securities Purchase Agreement (the “Amendment”), dated as of
[March] [30], 2011 (the “Amendment Effective Date”), is entered into by and
between DayStar Technologies, Inc., a Delaware corporation (the “Company”), and
Socius CG II, Ltd., a Bermuda exempted company (including its designees,
successors and assigns, the “Investor”). This Amendment amends certain
provisions under that certain Securities Purchase Agreement, dated as of
February 2, 2011 (the “Securities Purchase Agreement”), between the Company and
the Investor. Capitalized terms used in this Amendment not otherwise defined
herein shall have the meanings ascribed to such terms in the Securities Purchase
Agreement.

RECITALS:

WHEREAS, Section 6.5 of the Securities Purchase Agreement provides that no
provision the Securities Purchase Agreement may be amended except by a written
instrument signed by the Company and the Investor; and

WHEREAS, the Company and the Investor desire to clarify the terms of the
Securities Purchase Agreement to provide that, on each Tranche Notice Date, the
Additional Investment Right shall automatically vest and be exercised in an
amount equal to the Additional Investment Shares.

AGREEMENT:

NOW, THEREFORE, in consideration of the foregoing and the promises and covenants
contained herein, and for other good and valuable consideration, the receipt of
which is hereby acknowledged, the parties hereto agree to amend the Securities
Purchase Agreement as follows:

1. Amendment to Section 2.3(c)(ii) of Securities Purchase Agreement. Section
2.3(c)(ii) of the Securities Purchase Agreement is hereby deleted in its
entirety and replaced with the following text:

“(ii) Additional Investment Shares. On each Tranche Notice Date, Investor shall
become obligated, pursuant to a right that automatically vests and becomes
exercised on such Tranche Notice Date (each, an “Additional Investment Right”),
to purchase that number of shares of Common Stock (“Additional Investment
Shares”) equal in dollar amount to 100% of the Tranche Amount set forth in the
Tranche Notice at the price per share as determined by the immediately following
sentence. The exercise price per share of the Additional Investment Right shall
be as follows: (i) until the first Tranche Notice Date, the Closing Bid Price as
of the close of trading on the Effective Date, and (ii) on and after the first
Tranche Notice Date and each subsequent Tranche Notice Date, an amount per share
equal to the Closing Bid Price of a share of Common Stock on the Trading Day
immediately preceding the applicable Tranche Notice Date. The purchase of
Additional Investment Shares must occur no later than sixty (60) calendar days
following the Tranche Notice Date, and such purchases may occur from time to
time within such sixty calendar day period on such days as determined by the
Investor. Investor shall document the automatic exercise of the Additional
Investment Right by delivering an Investment Right Exercise Notice to the
Company and shall pay for the Additional Investment Shares in cash, or through
the issuance of a recourse note in the form attached as Exhibit G to this
Agreement. An Investment Right Exercise Notice in respect of an automatic
exercise of the Additional Investment Right, and the payment of the exercise
price in respect of such Investment Right Exercise Notice, shall be delivered on
or before 4:00 p.m., New York City time, on the Trading Day immediately
following the date on which the Tranche Notice is deemed to have been
delivered.”

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2. Effective Time. This Amendment shall become effective as of the Amendment
Effective Date.

3. Effect of Amendment. Except as expressly modified by this Amendment, the
Securities Purchase Agreement shall remain unmodified and in full force and
effect.

4. Governing Law. This Amendment shall be governed by and construed under the
laws of the State of New York.

5. Severability. If any provision of this Amendment shall be or shall be held or
deemed by a final order by a competent authority to be invalid, inoperative or
unenforceable, such circumstance shall not have the effect of rendering any
other provision or provisions herein contained invalid, inoperative or
unenforceable, but this Amendment shall be construed as if such invalid,
inoperative or unenforceable provision had never been contained herein so as to
give full force and effect to the remaining such terms and provisions.

6. Counterparts. This Amendment may be executed in any number of counterparts
and signatures delivered by facsimile, each of which shall be deemed an
original, but all of which together shall constitute one instrument.

[Signature Pages Follow]

 

2

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IN WITNESS HEREOF, the parties hereto have executed this Amendment as of the
date first written above.

 

DAYSTAR TECHNOLOGIES, INC.

By:

 

/s/ Christopher T. Lail

Name:

  Christopher T. Lail

Title:

  Chief Financial Officer

 

SOCIUS CG II, LTD. By:  

/s/ Terren Peizer

Name:   Terren Peizer Title:   Managing Director

[Signature Page – Amendment to Securities Purchase Agreement]