Single-cell omics are providing critical insights into plenty of biological processes such as development, aging, tissue heterogeneity, immune surveil-lance and disease pathogenesis. While signiﬁcant progress has been made in single-cell transcriptome and genome, the ﬁeld of single-cell proteom-ics (SCP) faces unique challenges. Proteins are much more complicated: their quantities are not always consistent with their RNAs level and their functions are always regulated by diverse modiﬁcations. Nevertheless, due to their pivotal role in cellular function, there is an urgent need for high-throughput approaches for single-cell proteomics analyses.
Unlike DNA and RNA, proteins cannot be easily ampliﬁed, posing a substantial challenge for unbiased, single-cell whole proteome analysis. Currently, there are limited methods available to address this issue. Mass-spectrometry(MS)-based single-cell proteomics has demonstrated prom-ising results: however, the success of such analyses heavily depends on the effectiveness of preceding steps involving single-cell sorting and sample pre-processing, as the quality of these procedures profoundly impacts the overall analytical outcome.