acid extraction and amplification, sequencing library preparation,
and sequencing and bioinformatic data analysis (Fig.1).1.1 Single-Cell
Isolation
Single-cell analyses rely on various molecular measurements of a
single cell. Although many technologies depending on single cells
have been developed, ensuring that a sample contains only a single
cell remains technically challenging. The first key step is to generate
a single-cell suspension, which varies considerably between tissue
types, and optimization is required to ensure analysis of a viable and
unbiased cell population. When tissue complexity or handling pro-
hibits intact cell isolation, suspensions of single nuclei can be
prepared alternatively [6, 7], which have been demonstrated in
(epi)genomic and transcriptomic analyses [8]. Various approaches
are available for isolating single cells from a suspension, of which we
briefly introduce the five most commonly used ones.Fig. 1Schematic overview of multiple single-cell sequencing technologies. Special steps are highlighted by
different colors for multiple omics
328 Yungang Xu and Xiaobo Zhou