The usefulness of different anti-proliferating cell nuclear antigen monoclonal antibodies as S-phase probes in flow cytometric analysis was evaluated after various fixation procedures on human cell lines. With a newly developed detergent extraction/fixation method the monoclonal antibody PC10 acted as a selective S-phase marker. A total of 27 human hematopoietic tumors were analyzed using PC10, and all exhibited the characteristic S-phase recognition pattern. The percentage of PC10-positive cells was easily calculated and showed strong correlation to the fraction of S-phase cells determined from DNA histograms. Using alternative fixation procedures PC10, on the other hand, could recognize all actively cycling cells, a feature also observed for the monoclonal antibodies, 19A2 and TOB7.
This study was supported by grants from the Swedish Cancer Society (90 1127), the Lions Cancer Research Foundation, and the Medical Faculty, University of Umeå.