Single Cell Isolation and Analysis

Abstract

Individual cell heterogeneity within a population can be critical to its peculiar function and fate. Subpopulations studies with mixed mutants and wild types may not be as informative regarding which cell responds to which drugs or clinical treatments. Cell to cell differences in RNA transcripts and protein expression can be key to answering questions in cancer, neurobiology, stem cell biology, immunology, and developmental biology. Conventional cell-based assays mainly analyze the average responses from a population of cells, without regarding individual cell phenotypes. To better understand the variations from cell to cell, scientists need to use single cell analyses to provide more detailed information for therapeutic decision making in precision medicine. In this review, we focus on the recent developments in single cell isolation and analysis, which include technologies, analyses and main applications. Here, we summarize the historical background, limitations, applications, and potential of single cell isolation technologies.

Keywords: analysis; heterogeneity; isolation; sequencing; single cell.

Figure 1

Overview of single-cell isolation technologies discussed in the section. (A) Schematic of fluorescence-activated cell sorting. The suspended labeled cells are passed as a stream in droplets with each containing a single cell in front of a laser. The fluorescence detection system detects the fluorescent and light scatter characteristics. Based on their characteristics, the instrument applies a charge to the droplet containing a cell of interest and an electrostatic deflection system facilitates collection of the charged droplets into different collecting tubes. Cells labeled with green, purple, and yellow indicate different cell types. (B) Schematic of magnetic-activated cell sorting. Cells of interest are labeled with specific antibody conjugated magnetic beads. An external magnetic field is used to separate the labeled cells from the cell suspension. S and N indicate magnetic field. (C) Schematic of laser capture microdissection. The technique utilizes a laser which fired through the cap over the cells of interest to melt the membrane to let the cells adhere to the melted membrane. When the cap is removed, captured cells are removed, leaving the unwanted cells behind. (D) Schematic of manual cell picking. The cells of interest are monitored under a microscope. By using a glass pipette connected to a micromanipulator, single cells can be collected and transferred to a new tube for following analysis. (E) Schematic of microfluidic used for single cell isolation. Before starting the experiments, cells need to be dissociated then flow into a chip. Thus, the cells may be separated into different tubes containing only one cell.