Dual immunofluorescence - new frontiers in cell analysis and sorting.

Investigations of the nature and functions of the immune system and its cell populations have been revolutionized by the techniques of fluorescence-activated cell sorting (FA CS) and flow cytometry. Over the last few years, however, it has become increasingly clear that making only a single immunofluorescence measurement on each cell is not adequate for many investigations of lymphoid cell subpopulations. In this review the authors discuss why adequate resolution of functional subsets will increasingly require multiparameter definition including measurements on two or more fluorescent labels.