When big fish Johnson & Johnson announced plans to swallow little fish Centocor in July, it was more than just a typical transaction in biotechnology's food chain. It marked, at least indirectly, the latest chapter in one of biotech's most intriguing and edifying shaggy-dog stories.

Centocor, based in Malvern, Pa., had always been one of those "coulda, shoulda" players in the biotech world. In the game early, well-capitalized and with good scientific talent, the company always seemed poised to join the first echelon of biotech startups. But it never quite made the ranks of the Amgens and Genentechs.