Diagnostics player Opko Health is buying Bio-Reference Laboratories for 2.75 shares of its stock for every share of Bio-Reference. The deal values Bio-Reference at $1.47 billion, according to Opko, which plans to amp up sales of the 4Kscore test, a blood test that provides a patient's specific personalized risk score for aggressive prostate cancer. Opko's stock dropped 7% on the news. The deal is expected to close in the second half of this year. Release