A method for detecting protein expression in single cells using the C1™ Single-Cell Auto Prep System (TECH2P.874)

Recent improvements in microfluidics and biochemistry have enabled single-cell molecular analysis, providing new insight into the heterogeneity of cell populations. The C1 Single-Cell Auto Prep System is an automated platform that streamlines the isolation and processing of 96 individual, live cells for RNA and DNA analysis. Single-cell protein profiling is a direct complement to genomic analysis as it provides additional insights into key molecular mechanisms and system biology. To enable this, we adapted a highly multiplexed protein detection system (Proseek Multiplex Oncology, Olink Bioscience) for use on the C1 System. We analyzed 192 individual cells from two human promyelocytic leukemia cell lines (HL60 and K562) and compared these result against 16 FACS-sorted cells in tube format. These results indicated that four key proteins (i.e. CASP3, CSTB, CD69 and MPO) are differentially expressed between the two cell lines and vary from cell-to-cell. For example, the human protein MPO, produced by neutrophils for their microbicidal activity, was differentially expression between individual HL60 and K562 cells, suggesting varying levels of neutrophil activation within the cell populations. This work demonstrates highly-multiplexed protein detection at the single-cell level and shows promise to have sufficient sensitivity, reproducibility and scale to effectively interrogate a statistically significant numbers of individual cells.