Whole-animal imaging of neural activity

Cell-to-cell heterogeneity is important in many biological processes. Although genomic and transcriptomic approaches to detect this heterogeneity are available, measuring the proteomes of single cells presents a much greater challenge. Herr, Schaffer and colleagues describe a western blotting approach for single cells, allowing the multiplex detection of up to 11 proteins per cell for ~2,000 cells in less than four hours. Their platform uses a glass slide coated with a photoactive gel containing an array of 6,720 microwells. Single cells are allowed to settle into the microwells, where they are lysed. The proteins are separated by electrophoresis; they are then immobilized by photo-cross-linking of the gel and, finally, detected with antibodies. The authors used the approach to study targeted protein expression variability during differentiation of rat neural stem cells. Article p749