<title>Molecular cytometry: analysis of proteins in single cells</title>

Abstract

Molecular cytometry refers to ultrasensitive analysis tools that are used to separate and identify entire classes of molecules in single cells. Recently, we described two molecular cytometry methods to analyze proteins at the single cell level. The first one was based on capillary gel electrophoresis with sheath-flow cuvette laser-induced fluorescence (LIF). A vacuum pulse was employed to introduce a single HT29 human colon cancer cell into the capillary. Once the cell was lysed, proteins were denatured with SDS, labeled with 3-(2-furoyl)-quinoline-2-carboxaldehyde (FQ), and then separated according to their size by using pullulan as the sieving matrix. The second one was based on submicellar capillary electrophoresis with sheath-flow cuvette LIF. Once a single cell was introduced and lysed, the cellular proteins were labeled with FQ and then separated in a submicellar buffer. This method has been applied to analysis of proteins in a single HT29 human cancer cell as well as single-cell stage Caenorhabditis elegans embryo.