Simultaneous analysis of cell surface antigens, bromodeoxyuridine incorporation and DNA content

A method has been developed for correlating the presence of cell surface markers with bromodeoxyuridine (BrdUrd) uptake. We have found that paraformaldehyde fixation will maintain immunofluorescent cell surface staining through acid denaturation that is necessary for anti-BrdUrd reactivity to single-stranded DNA. In addition, the forward angle light scattering was maintained, even though the cells had been exposed to 2N HCl and detergent. The protocol was tested on three model systems: mouse thymus, a human cell line (CCRF-SB), and peripheral blood leukocytes. It was found that there was no specific loss of lymphocyte subsets.