DNA flow cytometric values in bladder carcinoma biopsies obtained from fresh and paraffin‐embedded material

Abstract
DNA‐histograms were obtained by flow cytometry (FCM) of nuclei prepared from fresh bladder carcinoma biopsies and from 100 μm sections of paraffin‐embedded material from the same biopsies. Linear regression analysis of ploidy values from fresh material versus those from paraffin blocks showed excellent correlation (R2=0.957). Owing to the high background, the paraffin‐embedded material was less suited for analysis of S‐phase fraction. It is concluded that DNA FCM of nuclei obtained from paraffin‐embedded bladder carcinoma biopsies yields reliable results concerning ploidy, but does not permit evaluation of the S‐phase fraction.