Beckman Coulter, a biomedical testing company, announced yesterday that it would acquire San Diego-based Biosite for $1.55 billion. The purchase will increase Beckman Coulter’s presence in the diagnostic-test market, but industry watchers are saying the Fullerton, CA buyer may have overpaid. According to the Associated Press, “Piper Jaffray analyst William Quirk downgraded Beckman Coulter stock after the purchase. In a client note, he said the price is high, and revenue from Biosite’s biggest earner, the B-type natriuretic peptide tests for heart failure, is expected to grow at levels below its competitors.” Beckman Coulter chief Scott Garrett defended the deal, telling The Wall Street Journal it’s “a great opportunity, even at a price that appears at first glance to be quite a high premium.” Beckman Coulter will acquire all of Biosite’s outstanding common stock in a cash tender offer of $85.00 per share, or approximately $1.55 billion on a fully diluted share basis. The proposed transaction is expected to immediately accelerate Beckman Coulter’s revenue growth, improve operating margins and be accretive to GAAP earnings in 2008 and beyond. Full release.