UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

Information Statement Pursuant to Rules 13d-1 and 13d-2

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Ventana Medical Systems, Inc.
(Name of Issuer)

Common Stock
(Title of Class of Securities)

92276H106
(CUSIP Number)

December 31, 2007
Date of Event Which Requires Filing of the Statement

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

o	Rule 13d-1(b)

x	Rule 13d-1(c)

o	Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Page 1 of 9

CUSIP NO. 92276H106

13G

Page 2 of 9 Pages

1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Investment Group, L.L.C.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited liability company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,581,924 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 4.6%⁽¹⁾ as of December 31, 2007.
12.	TYPE OF REPORTING PERSON OO; HC

(1)	Based on 34,662,691 outstanding shares of the Common Stock of Issuer, as reported in the Issuer’s Quarterly Report on Form 10-Q for the period ended September 30, 2007, as filed with the Securities and Exchange Commission on October 23, 2007.

Page 2 of 9

CUSIP NO. 92276H106

13G

Page 3 of 9 Pages

1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Limited Partnership
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware limited partnership
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,581,924 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 4.6%⁽²⁾ as of December 31, 2007.
12.	TYPE OF REPORTING PERSON PN; HC

(2)	See footnote 1 above.

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CUSIP NO. 92276H106

13G

Page 4 of 9 Pages

1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Kenneth Griffin
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,581,924 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 4.6%⁽³⁾ as of December 31, 2007.
12.	TYPE OF REPORTING PERSON IN; HC

(3)	See footnote 1 above.

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CUSIP NO. 92276H106

13G

Page 5 of 9 Pages

1.	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Citadel Equity Fund Ltd.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) x (b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands company
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 1,581,924 shares
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER See Row 6 above.
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON See Row 6 above.
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) Approximately 4.6%⁽⁴⁾ as of December 31, 2007.
12.	TYPE OF REPORTING PERSON CO

(4)	See footnote 1 above.

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CUSIP NO. 92276H106

13G

Page 6 of 9 Pages

Item 1(a)

Name of Issuer: VENTANA MEDICAL SYSTEMS, INC.

1(b)

Address of Issuer’s Principal Executive Offices:

1910 E. Innovation Park Drive

Tucson, Arizona 85755

Item 2(a)

Name of Person Filing⁽⁵⁾

Item 2(b)

Address of Principal Business Office

Item 2(c)

Citizenship

	Citadel Investment Group, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited liability company

	Citadel Limited Partnership
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Delaware limited partnership

	Kenneth Griffin
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	U.S. Citizen

	Citadel Equity Fund Ltd.
	c/o Citadel Investment Group, L.L.C.
	131 S. Dearborn Street
	32nd Floor
	Chicago, Illinois 60603
	Cayman Islands company

2(d)

Title of Class of Securities:

Common Stock, par value $0.001.

2(e)

CUSIP Number: 92276H106

(5) Citadel Holdings Ltd., a Cayman Islands company (“CH”), is majority owned by Citadel Kensington Global Strategies Fund Ltd., a Bermuda company (“CKGSF”). Citadel Equity Fund Ltd. (“CEF”) is a subsidiary of CH. CKGSF and CH do not have control over the voting or disposition of securities held by CEF.

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CUSIP NO. 92276H106

13G

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Item 3

If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a:

(a)

[__]

Broker or dealer registered under Section 15 of the Exchange Act;

(b)

[__]

Bank as defined in Section 3(a)(6) of the Exchange Act;