RNA and DNA content of isolated nuclei from bladder irrigation specimens as measured by flow cytometry

Cell nuclei were isolated from bladder irrigation specimens from urologic patients having neoplastic disease and distinct aneuploid tumor populations with ploidy levels greater than 2. 0c . The isolated nuclei were subsequently stained with acridine orange, and their fluorescence was measured by flow cytometry. The RNA-DNA frequency distributions of nuclei were compared to those of whole, intact cells from the identical specimens. A comparison of RNA content revealed distinct subpopulations of aneuploid G1 tumor cells with different RNA content. The low and high RNA subpopulations were present in both whole cells and intact nuclei. The overall profile regarding ploidy levels of tumors as well as cell cycle distributions were comparable in both whole cells and nuclei. The resolution of DNA content, however, was significantly better in nuclei preparations. This fact made it easier to distinguish aneuploid cells with near-diploid values of DNA content.