FLOW CYTOMETRY OF ISOLATED-NUCLEI PREPARED FROM 9L RAT-BRAIN TUMOR

  • 1 January 1979
    • journal article
    • research article
    • Vol. 41  (1) , 72-76
Abstract
Nuclei isolated by grinding 9L rat brain tumors gave a DNA distribution consisting of a 2C DNA peak due to noncycling normal cells and a bimodal distribution beginning at about 4C DNA due to the cycling tumor cells. Autoradiographic studies of nuclei from rats that received a pulse of 3H-TdR [thymidine] in vivo confirmed that the majority of proliferating cells were in the bimodal part of the distribution. The fraction of cells in S-phase determined from the DNA distributions was 15.3%. This is consistent with a labeling index of 18% determined from autoradiographs of tumor tissue and an S-phase fraction of 17% determined from a fraction of labeled mitosis analysis (assuming that all of the 53% noncycling cells are in Go). By autoradiographic analysis of cells sorted from the tumor''s mid-S-phase region, was determined that only 58% of these cells were labeled. This is attributed mostly to the presence of fluorescent debris from necrotic nuclei in this part of the distribution.