By necessity or convenience, almost everything we know about biochemistry and molecular biology derives from bulk behavior: From gene regulation to Michaelis-Menten kinetics, we understand biology in terms of what the “average” cell in a population does.
But, as Jonathan Weissman of the University of California, San Francisco, points out, “A lot gets lost in the average.” For instance, “The census might say, the average family has 1.9 children, but no family has 1.9 children.” Similarly, though most bacterial cells in a culture may behave in one way—growing preferentially on glucose, for instance—a small number may exist in a different state, the better to protect the population against the vagaries of future environmental conditions.
Over the past few years, researchers have been eschewing bulk studies and pushing technological limitations to bring their studies of genomics, genetics, RNA transcription and translation, proteins, and metabolites down to this single cell level. The ...
