TISSUE DISAGGREGATION FOR FLOW CYTOMETRIC DNA ANALYSIS - COMPARISON OF FINE-NEEDLE ASPIRATION AND AN AUTOMATED MECHANICAL PROCEDURE

Flow cytometric DNA analysis was performed on unfixed frozen samples f rom 56 breast cancer patients. From each patient, two samples were ana lyzed, The only difference in the handling of the paired samples was t he mechanical disaggregation of one sample by fine-needle aspiration c ompared to an automated mechanical disaggregation method (Medimachine) of the other sample, With the two methods for tissue disaggregation, the same resolution of the DNA histograms was obtained, indicated by m edian coefficients of variation (CV) of 1.5% for the DNA diploid G(1) peaks. Also, the frequencies of DNA diploid and aneuploid cases as wel l as the fractions of DNA aneuploid cells were comparable. This indica tes that the two methods did not differ in ability to detect DNA aneup loid tumor clones. Automated mechanical disaggregation resulted in DNA histograms with significantly less debris and with lower S-phase frac tions, In practice, the procedure of automated mechanical disaggregati on was rapid, easy, and safer because of minimal handling of the unfix ed tissue compared to the fine-needle aspiration. (C) 1996 Wiley-Liss, Inc.