RNA sequencing (RNA-seq) is a genomic approach for the detection and quantitative analysis of messenger RNA
molecules in a biological sample and is useful for studying cellular responses. RNA-seq has fueled much discovery
and innovation in medicine over recent years. For practical reasons, the technique is usually conducted on samples
comprising thousands to millions of cells. However, this has hindered direct assessment of the fundamental unit of
biology—the cell. Since the first single-cell RNA-sequencing (scRNA-seq) study was published in 2009, many more
have been conducted, mostly by specialist laboratories with unique skills in wet-lab single-cell genomics, bioinformatics,
and computation. However, with the increasing commercial availability of scRNA-seq platforms, and the rapid ongoing
maturation of bioinformatics approaches, a point has been reached where any biomedical researcher or clinician can
use scRNA-seq to make exciting discoveries. In this review, we present a practical guide to help researchers design their
first scRNA-seq studies, including introductory information on experimental hardware, protocol choice, quality control,
data analysis and biological interpretation.