Bivariate Flow Cytometric Analysis of Proliferation Associated Nuclear Antigens in Solid Tumor Cells

AbstractBivariate flow cytometry was used for analysis of DNA content and proliferation associated nuclear antigens (PCNA, Ki-67, p105, p145, p120) in the T24 cell line, in 34 fresh solid tumors, and in 4 normal tissue specimens. Antigens were analyzed in both fixed and unfixed cells. In solid tumors and T24 cells, Larsen's washless method yielded the highest expression of PCNA and Ki-67, whereas p105, p145, and p120 were best demonstrated by other methods. Antigen expression was generally lower in normal tissues than in solid tumor (P < 0.05), but there was great variation in antigen expression among all tumor types. Antigen expression did not correlate with DNA ploidy or with percent S phase. The data suggest that cell fixation methods must be optimized for each antigen studied. Our results demonstrate the feasibility and methodology of dual flow cytometry on minute clinical specimens by the washless method. (The J Histotechnol 18:17, 1995)