Microphotometry in immunofluorescence

Abstract

A specially sensitive version of the Reichert microphotometer provides a means of obtaining accurate measurements of the emission of immunofluorescent microscopical preparations. The fluorescence of single particles down to 0·8 μ in diameter may be measured with all background excluded. The photometer has permitted determinations of titre of antisera, assessment of the validity of conventional visual estimation of fluorescence, and comparative studies of fluorescence intensity and fading under a variety of conditions. Preliminary studies by double immunofluorescent staining of two distinct antigenic constituents of cells which might be present either separately or together, suggest future value in investigations of cell differentiation and dedifferentiation.