SINGLE-CELL ANALYSIS OF THE EXPRESSION OF A NUCLEAR-PROTEIN, SCIP, BYFLUORESCENT IMMUNOHISTOCHEMISTRY VISUALIZED WITH CONFOCAL MICROSCOPY

A widely applicable method for the accurate quantification or semiquan tification of macromolecules at the level of individual cells is descr ibed and validated; this is a method which may considerably facilitate the study of many biological processes. This method relies on measuri ng fluorescent emission in immunocytochemically labelled cells with a confocal microscope. Emission is related quantitatively to the level o f the fluorophore by the combination of an analysis of the polarizatio n of the fluorescent emission and fluorophore ratioing methods. The me thod was applied to the study of the expression of the suppressed cycl ic AMP-induced POU protein (SCIP) transcription factor in glial cells of the central nervous system. In particular, the method allowed the s tudy of transcription factor expression in defined cells present in he terogeneous cultures and in cell types which cannot be isolated in suf ficient numbers for biochemical analysis using conventional techniques .