They identified signals that white blood cells use to control their behaviour, then one by one disabled those signals — discovering that one particular molecule called ERK5 could be manipulated to encourage white blood cells either to throw out pathogens better or to keep them inside and try to kill them for longer. (sciencedaily.com)
Make the strands with particular DNA sequences and they will unravel on contact with particular molecules — say, those on a diseased cell. (newscientist.com)
Spectroscopy, X-ray crystallography and molecular genetics combine to give a detailed picture of events in photosynthesis and show how particular molecules contribute to the process (scientificamerican.com)