8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) December 9, 2004

INVITROGEN CORPORATION

(Exact name of registrant as specified in its charter)

Delaware	0-25317	33-0373077
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

1600 Faraday Avenue, Carlsbad, CA	92008
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code (760) 603-7200

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

x Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Section 8 – Other Events

Item 8.01 Other Events.

On December 9, 2004, Invitrogen Corporation (the “Company”) issued a press release announcing it has completed its exchange offer with respect to the Company’s 2.0% Convertible Senior Notes due 2023 and the Company’s 1.5% Convertible Senior Notes due 2024. The press release is attached hereto as Exhibit 99.1.

Section 9 - Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits.

(a) Not applicable.

(b) Not applicable.

(c) Exhibits.

Exhibit No.	Description
99.1	December 9, 2004 Press Release by Invitrogen Corporation

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Invitrogen Corporation
	(Registrant)
Date December 9, 2004
	/s/    JOHN A. COTTINGHAM
	John A. Cottingham
	Senior Vice President, General Counsel and Secretary

EX-99.1

Exhibit 99.1

Press Release

Filed by Invitrogen Corporation pursuant to Rule 425

under the Securities Act of 1933, and Rule 13e-4

under the Securities Exchange Act of 1934

Subject Company: Invitrogen Corporation

Commission File No. 000-25317

Investor and Financial Contacts:

Adam S. Taich

Vice President, Investor Relations

(760) 603-7208

INVITROGEN COMPLETES EXCHANGE OFFER

FOR ITS SENIOR CONVERTIBLE NOTES

Carlsbad, CA, December 9, 2004—Invitrogen Corporation (Nasdaq: IVGN) announced today that it has completed its offer to exchange up to $350 million of new 2.0% senior convertible notes due 2023 (the “New 2.0% Notes”) for an equal principal amount of its currently outstanding 2.0% senior convertible notes due 2023 (the “Existing 2.0% Notes”), and up to $450 million of new 1.5% senior convertible notes due 2024 (the “New 1.5% Notes”) for an equal principal amount of its currently outstanding 1.5% senior convertible notes due 2024 (the “Existing 1.5% Notes”). In addition, Invitrogen will make a cash payment of $2.50 per $1,000 principal amount of notes accepted in the offer. The exchange offer expired at midnight, New York City time, on December 8, 2004.

As of the expiration of the exchange offer, approximately $301.35 million aggregate principal amount (including $10.56 million of notes tendered pursuant to the procedures for guaranteed delivery) representing approximately 86.1 percent of the outstanding principal amount of the Existing 2.0% Notes and $424.60 million aggregate principal amount (including $21.43 million of notes tendered pursuant to the procedures for guaranteed delivery) representing approximately 94.4 percent of the outstanding principal amount of the Existing 1.5% Notes have been tendered for exchange. All of the Existing 2.0% Notes and Existing 1.5% Notes that were properly tendered have been accepted for exchange. The exchange offer is expected to be consummated on December 14, 2004, following which, approximately $48.65 million aggregate principal amount of the Existing 2.0% Notes and approximately $25.40 million aggregate principal amount of the Existing 1.5% Notes will remain outstanding.

Investors and security holders may obtain the prospectus and other materials related to the exchange offer free of charge at the Securities and Exchange Commission’s website (www.sec.gov) or through the information agent for the exchange offer, MacKenzie Partners, Inc., 105 Madison Avenue, New York, New York 10016 (telephone number: 212-929-5000 (call collect) or 800-322-2885 (U.S. toll free)). Banc of America Securities LLC is the exclusive dealer manager in connection with the exchange offer. Questions regarding the exchange offer may be directed to Banc of America Securities LLC, Equity-Linked Liability Management at 888-583-8900, x2200 (U.S. toll-free) and 212-933-2200 (call collect).

A registration statement relating to the securities to be issued in the exchange offer has been filed with the Securities and Exchange Commission and has been declared effective.

Safe Harbor Statement

Invitrogen’s statements in this press release contain forward-looking statements regarding the timing of the exchange. There can be no assurance that Invitrogen will complete the exchange offer on the anticipated terms or at all. Invitrogen’s ability to complete the exchange offer and Invitrogen’s business are subject to the risks described in its filings with the Securities and Exchange Commission.

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