Single-cell biology: The power of one

Abstract

Pick a paper, any paper. If it involves the protein, nucleic acid, or metabolite content of bacterial or eukaryotic cells, there's likely a section detailing how those cells were grown in culture. Cell culture is how researchers expand cells to harvest macromolecules or to interrogate their responses to changing conditions or chemical treatment. Inherent in such work is the assumption that all the cells in a dish are identical—by growing them in culture, the researcher is simply amplifying the signal. But that isn't always true. Subtle differences at the molecular level can yield significant variation in cellular behavior, but until recently researchers had no way to probe that variability. Today, they do.