On Apr. 30, 2012, Hologic announced the acquisition of San Diego-based Gen-Probe, a molecular diagnostics company, for $3.7 billion, or $82.75 a share. The deal combined Gen-Probe’s leading diagnostics for sexually transmitted diseases and its blood screening business with Hologic’s global market presence and distribution primarily targeting women’s health.

Under the deal, Hologic will pay $82.75 for each Gen-Probe share, a 20 percent premium to the stock’s closing price on Friday. Gen-Probe shares surged 18.7 percent to $81.57 in afternoon trading on Monday. Shares of Hologic, which is financing the deal with a combination of cash and debt, fell 10.1 percent to $19.08. Earlier on Monday the company reported quarterly revenue that fell short of expectations, and analysts said Hologic was paying full price for Gen-Probe.

The deal comes nearly a year after Gen-Probe put itself up for sale and Novartis AG , which already had a partnership with the company, pulled out of the bidding process.