Isolation and characterization of transfected cell lines expressing neurotransmitter receptors using a calcium dye and flow cytometry

Abstract An important early application of flow cytometry was to detect subpopulations of cells marked with a fluorescent ligand. This methodology was also used to sort out the targeted cells from the whole population. Traditionally, primary antibodies developed against unique cell markers were coupled to fluorescently tagged secondary antibodies and used to identify subpopulations of cells. In many cases, these markers were cell-type specific for receptors on the plasma membrane. For example, antibodies against immunoglobin receptors specific for subpopulations of lymphocytic T cells were usefully exploited as a way to detect changes in the expression of T cell subsets in different disease states (1). However, since in many cases it has proved difficult to generate antibodies to receptors for hormones, neurotransmitters, and neuromodulators, investigators have been motivated to explore other methods, not dependent on antibodies, with which to identify cells expressing specific receptors on their surface.