Hologic Inc. continues to strengthen its diagnostics businesses via tuck-ins, this time with the acquisition of Diagenode SA for $159 million. The Belgium-based developer of molecular assays and epigenetics products counts more than 30 real-time polymerase chain reaction (PCR) tests in its portfolio. Marlborough, Mass.-based Hologic has been on a spending spree in recent months. In January, the company completed the acquisition of Somatex Medical Technologies GmbH for about $64 million and agreed to buy molecular diagnostics company Biotheranostics Inc. for $230 million.