A major limiting factor in biological research is the challenge of quickly and accurately identifying specific proteins in a single cell. The workhorse single-cell tool, flow cytometry, suffers from limited performance, while the highly-specific Western blot has not been able to measure proteins in a single cell.
Using microfluidic design and commonly-available materials, members of bioengineering professors Dave Schaffer and Amy Herr’s labs have introduced a new tool that allows the highly specific measurements made with Western blots to be applied to single cells. Their approach advances microarray-like formats to include tiny electrophoretic separations to sort proteins by size, followed by the standard antibody-based detection. The single-cell Western (scWestern) detects as many as eleven protein targets in one cell. The tool can assay about 2,000 individual cell in under four hours.
Having the capability to measure single-cell protein levels with high specificity could change the way we probe protein-mediated signaling within the cell. Identification of fleeting interactions and similar but unique proteins are two major areas where the new measurements could assist. This could be especially useful in understanding stem cell differentiation and differences among rare cell types, like circulating tumor cells.
This research was published online in Nature Methods June 2014, with lead authors Alex Hughes (BioE Phd 2013) and Dawn Spelke (BioE graduate student). In the first week of publication the article was ranked the #1 most emailed and #4 most read.