It's been a little while but here's a new "name the biologist". It's still techniques oriented, until it turns into something else, so the list of candidates should be shrinking
As for the last instalment that was none other than Paul Erhlich another Nobel Prize winner who among many other contributions popularised the "magic bullet" theory in which the magic bullet was a compound carrying a toxin that would selectively target and kill a disease-causing organism. This is partly seen in monoclonal antibodies. Erhlich also developed staining techniques for identifying different blood cell types leading to the characterisation of several blood diseases. He was also a pioneer in chemotherapy. A pretty spectacular career.