After more than a year of less-than-clandestine sale efforts, Johnson & Johnson ($JNJ) has found a buyer for its diagnostics unit, signing a $4.2 billion deal with Carlyle Group. Despite hauling in more than $2 billion in annual revenue, J&J's diagnostics business hasn't grown as fast as the market, reflecting the company's focus on established blood tests instead of en vogue molecular diagnostics. Now the company is looking to hone its operation on higher-growth areas, and analysts believe J&J may just be getting started, suggesting the company may prune some of its less promising units in order to better focus on its booming pharma segment. Article