Canoga Park, Calif.-based One Lambda makes diagnostic tests used by transplant centers for tissue typing and to help determine compatibility of potential donors and recipients. The privately held company, in business since 1984, generated $182 million in sales last year and employs more than 1,400 worldwide.

The purchase price includes a three-year retention program established by One Lambda as well as a one-year earnout provision based on achievement of certain financial targets. Waltham, Mass.-based Thermo Fisher said it would fund the deal with cash on hand and new debt, and said it expects the purchase to begin contributing to earnings immediately upon its anticipated fourth-quarter close.

Thermo Fisher, a $12 billion sales maker of medical diagnostic equipment, has since 2010 been engaged in a concerted effort to redefine itself via acquisitions. The company in recent years has completed a $3.5 billion buyout of Swedish diagnostics firm Phadia AB, a developer of blood-test systems that support the diagnosis and monitoring of allergy and autoimmune diseases; and a $2.1 billion acquisition of chromatography specialist Dionex Corp.

The company has also made several smaller purchases, including a May purchase of Doe & Ingalls Management LLC for $175 million, and has unloaded some laboratory testing assets.

Thermo Fisher CEO Marc N. Casper in a statement called One Lambda "an exciting addition to our specialty diagnostic portfolio," saying the purchase both complements existing company assets and should benefit from the buyer's greater reach.

"One Lambda gives us access to the attractive transplant diagnostics market and complements our existing immunosuppressant monitoring assays," Casper said. "It also offers the opportunity to leverage our global commercial infrastructure to serve growing transplant needs in emerging markets."

Thermo Fisher expects the deal to contribute 9 cents to 11 cents per share in 2013, and to generate upward of $15 million in revenue and cost synergies by 2015. The companies said they expect to increase Thermo Fisher's tax basis on the acquired assets at closing, an election that will result in annual cash tax savings of about $19 million over 15 years.

The tax benefit would lower the purchase price paid to a multiple of 2011 Ebitda of 8.7 times, down from 10.9 times Ebitda without the tax change. JPMorgan Securities LLC and Wilmer Cutler Pickering Hale and Dorr LLP advising Thermo Fisher, while One Lambda received advice from Perella Weinberg Partners LP and Sheppard Mullin Richter & Hampton LLP.