SC TO-T/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

Amendment No. 6

IRIS INTERNATIONAL, INC.

(Name of Subject Company (Issuer))

DAPHNE ACQUISITION CORPORATION

(Offeror)

An Indirect Wholly Owned Subsidiary of

DANAHER CORPORATION

(Offeror)

(Names of Filing Persons (identifying status as offeror, issuer or other person))

COMMON STOCK, PAR VALUE $0.01 PER SHARE

(Title of Class of Securities)

46270W105

(CUSIP Number of Class of Securities)

Jonathan P. Graham

Senior Vice President - General Counsel

Attila I. Bodi

Vice President and Chief Counsel, M&A

2200 Pennsylvania Avenue, N.W., Suite 800W

Washington, D.C. 20037-1701

(202) 828-0850

(Name, address, and telephone numbers of person authorized to receive notices and communications on behalf of filing persons)

Copies to:

Daniel Wolf, Esq.

David B. Feirstein, Esq.

Kirkland & Ellis LLP

601 Lexington Avenue

New York, NY 10022

(212) 446-4800

CALCULATION OF FILING FEE

Transaction Valuation(1)	Amount of Filing Fee(2)
$400,876,125	$45,940.40

(1) Estimated solely for purposes of calculating the amount of the filing fee. This amount is based on the offer to purchase all 20,557,750 outstanding shares of common stock of IRIS International, Inc. (“IRIS”), calculated on a fully diluted basis per information provided by IRIS, at a purchase price of $19.50 cash per share, as of September 18, 2012, the most recent practicable date.

(2) Calculated in accordance with Exchange Act Rule 0-11 by multiplying the transaction value by 0.0001146.

x Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the form or schedule and the date of its filing.

Amount Previously Paid: $45,940.40	Filing Party: Danaher Corporation
Form of Registration No.: Schedule TO	Date Filed: September 20, 2012

Check the appropriate boxes below to designate any transactions to which the statement relates:

x Third-party tender offer subject to Rule 14d-1.

¨ Issuer tender offer subject to Rule 13e-4.

¨ Going-private transaction subject to Rule 13e-3.

¨ Amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer. ¨

If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:

¨ Rule 13e-4(i) (Cross-Border Issuer Tender Offer)

¨ Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)

This Amendment No. 6 (this “Amendment”) to the Tender Offer Statement on Schedule TO (the “Schedule TO”) amends and supplements the Schedule TO filed by (i) Daphne Acquisition Corporation, a Delaware corporation (“Purchaser”), and an indirect wholly-owned subsidiary of Danaher Corporation, a Delaware corporation (“Parent”), and (ii) Parent, for all of the outstanding shares of common stock, par value $0.01 per share (the “Shares”) of IRIS International, Inc., a Delaware corporation (the “Company”), at a price of $19.50 per Share net to the seller in cash without interest and less any applicable withholding taxes, if any, upon the terms and conditions set forth in the offer to purchase dated September 20, 2012 (the “Offer to Purchase”), a copy of which is attached as Exhibit (a)(1)(A), and in the related letter of transmittal (the “Letter of Transmittal”), a copy of which is attached as Exhibit (a)(1)(B), which, together with any amendments or supplements thereto, collectively constitute the Offer.

All the information set forth in the Offer to Purchase is incorporated by reference herein in response to Items 1 through 9 and Item 11 in this Schedule TO, and is supplemented by the information specifically provided in this Schedule TO.

This Amendment No. 6 is being filed to amend and supplement Items 1, 4 and 12 as reflected below. Capitalized terms used and not otherwise defined in this Amendment shall have the meanings assigned to such terms in the Offer to Purchase or in the Schedule TO.

Items 1 and 4

Items 1 and 4 of the Schedule TO are hereby amended and supplemented by adding the following text thereto:

“On October 29, 2012, Parent and Purchaser extended the expiration of the Offer until 5:00 PM, New York City time, on Wednesday, October 31, 2012, unless further extended.

The Depositary has indicated that, as of 5:30 PM, New York City time, on October 29, 2012, approximately 15,807,016 Shares had been validly tendered and not validly withdrawn in the Offer, which represent approximately 86% of the Shares issued and outstanding.

On October 29, 2012, Parent issued a press release announcing the extension of the Offer. The full text of the press release is attached hereto as Exhibit (a)(1)(I) and is incorporated herein by reference.”

Item 12

Item 12 of the Schedule TO is amended and supplemented by adding the following exhibit:

Exhibit No.

(a)(1)(I) Press Release issued by Danaher Corporation, dated October 29, 2012.

SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

DAPHNE ACQUISITION CORPORATION
By	/s/ Robert S. Lutz
Name:	Robert S. Lutz
Title:	Vice President, Treasurer and Secretary
Date:	October 29, 2012
DANAHER CORPORATION
By	/s/ Frank T. McFaden
Name:	Frank T. McFaden
Title:	Vice President & Treasurer
Date:	October 29, 2012

EXHIBIT INDEX

Exhibit No.
(a)(1)(A)	Offer to Purchase, dated September 20, 2012.*
(a)(1)(B)	Letter of Transmittal (including Internal Revenue Service Form W-9).*
(a)(1)(C)	Notice of Guaranteed Delivery.*
(a)(1)(D)	Letter from the Information Agent to Brokers, Dealers, Commercial Banks, Trust Companies and Nominees.*
(a)(1)(E)	Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Nominees.*
(a)(1)(F)	Press Release of Danaher Corporation, dated as of September 17, 2012 (incorporated by reference to Exhibit 99.1 to the Schedule TO-C filed by Danaher Corporation with the Securities and Exchange Commission on September 17, 2012).*
(a)(1)(G)	Summary Advertisement as published on September 20, 2012.*
(a)(1)(H)	Press Release of Danaher Corporation, dated as of October 17, 2012.*
(a)(1)(I)	Press Release of Danaher Corporation, dated as of October 29, 2012.
(a)(5)(A)	Memorandum of Understanding, dated as of October 17, 2012 (incorporated by reference to Exhibit (a)(5)(B) to Amendment No. 3 to the Schedule 14D-9 filed by IRIS International, Inc. with the Securities Exchange Commission on October 17, 2012).*
(b)	Not applicable.
(c)	Not applicable.
(d)(1)	Agreement and Plan of Merger, dated as of September 17, 2012, by and among IRIS International, Inc., Danaher Corporation, and Daphne Acquisition Corporation (incorporated by reference to Exhibit 2.1 to the Form 8-K filed by IRIS International, Inc. with the Securities and Exchange Commission on September 17, 2012).*
(d)(2)	Tender and Support Agreement, dated as of September 17, 2012, by and among Danaher Corporation, Daphne Acquisition Corporation and certain stockholders of the Company party thereto (incorporated by reference to Exhibit 99.2 to the Form 8-K filed by IRIS International, Inc. with the Securities and Exchange Commission on September 17, 2012).*
(d)(3)	Confidentiality Agreement, dated as of April 4, 2012, by and between Beckman Coulter, Inc. and IRIS International, Inc.*
(e)	Not applicable.
(f)	Not applicable.
(g)	Not applicable.
(h)	Not applicable.

* Previously filed.

EX-99.A.1.I

Due to Severe Weather on the East Coast of the United States, Danaher Corporation Extends

Tender Offer for IRIS International, Inc. Until October 31, 2012

Washington, D.C., October 29, 2012 – Danaher Corporation (NYSE: DHR) (“Danaher”) announced today that, due to the effects of severe weather on the East Coast of the United States, it has extended the tender offer, through its wholly owned subsidiary Daphne Acquisition Corporation, for all outstanding shares of common stock of IRIS International, Inc. (NASDAQ: IRIS) (“IRIS”) to 5:00 p.m., New York City time, on October 31, 2012, unless further extended. The tender offer was previously scheduled to expire at 12:00 midnight, New York City time, on October 29, 2012.

The tender offer is being made in accordance with the previously announced Agreement and Plan of Merger, dated September 17, 2012, by and among Danaher, Daphne Acquisition Corporation and IRIS (the “Merger Agreement”). Except for the extension of the expiration date, all other terms and conditions of the tender offer remain unchanged.

The depositary for the tender offer has advised Danaher that, as of approximately 5:30 p.m., New York City Time, on October 29, 2012, stockholders of IRIS validly tendered approximately 15,807,016 shares of IRIS common stock (not counting as validly tendered, shares that were tendered through notice of guaranteed delivery and not actually delivered) representing approximately 86% of the IRIS shares outstanding.

This press release is neither an offer to purchase nor a solicitation of an offer to sell shares of IRIS.

About Danaher

Danaher is a science and technology leader that designs, manufactures, and markets innovative products and services to professional, medical, industrial, and commercial customers. Our premier brands are among the most highly recognized in each of the markets we serve. The Danaher Business System provides a foundation to our 59,000 associates around the world, serving customers in more than 125 countries. In 2011, we generated $16.1 billion of revenue. For more information please visit our website: www.danaher.com.

Notice to Investors

This announcement is neither an offer to purchase nor a solicitation of an offer to sell securities. Danaher and Daphne Acquisition Corporation have filed a tender offer statement with the SEC, and have mailed an offer to purchase, forms of letter of transmittal and related documents to IRIS stockholders. IRIS has filed with the SEC, and has mailed to IRIS stockholders a solicitation/recommendation statement on Schedule 14D-9. These documents contain important information that should be read carefully before any decision is made with respect to the tender offer. Those materials will be made available to IRIS security holders at no expense to them. In addition, all of those materials (and all other offer documents filed with the SEC) will be available at no charge on the SEC’s Web site: www.sec.gov.

Forward-looking statements

Statements in this release that are not strictly historical, including statements regarding the proposed acquisition of IRIS, the anticipated expiration date for the tender offer and any other statements regarding events or developments that we believe or anticipate will or may occur in the future, are “forward-looking” statements within the meaning of the federal securities laws, and involve a number of risks and uncertainties. There are a number of important factors that could cause actual events to differ materially from those suggested or indicated by such forward-looking statements and you should not place undue reliance on any such forward-looking statements. These factors include risks and uncertainties related to, among other things: general economic conditions and conditions affecting the industries in which Danaher

and IRIS operate; the uncertainty of regulatory approvals; the parties’ ability to satisfy the tender offer and merger agreement conditions and consummate the transaction; and Danaher’s ability to successfully integrate IRIS’ operations and employees with Danaher’s existing business. Additional information regarding the factors that may cause actual results to differ materially from these forward-looking statements is available in Danaher’s SEC filings, including Danaher’s Annual Report on Form 10-K for the year ended December 31, 2011 and Quarterly Report on Form 10-Q for the quarterly period ended September 28, 2012 as well as IRIS’ SEC filings, including IRIS’ Annual Report on Form 10-K for the year ended December 31, 2011 and Quarterly Report on Form 10-Q for the quarter ended June 30, 2012. These forward-looking statements speak only as of the date of this release and Danaher does not assume any obligation to update or revise any forward-looking statement, whether as a result of new information, future events and developments or otherwise, except as required by law.

Danaher contact:

Matt R. McGrew

Vice President, Investor Relations

Danaher Corporation

2200 Pennsylvania Avenue, NW

Suite 800W

Washington, D.C. 20037

Telephone: (202) 828-0850

Fax: (202) 828-0860