FEASIBILITY AND RELIABILITY OF FLOW-CYTOMETRY (FCM) DNA ANALYSIS OF FRESH AND FIXED URINE SAMPLES

The qualitative results of FCM DNA analysis on fresh and fixed urine s pecimens (28 and 97, respectively) from 68 normal subjects and 10 pati ents with a past history of bladder cancer were compared. FCM DNA eval uability was not significantly different in fresh and fixed samples (6 3% vs 73%, respectively) whereas mean CV was significantly higher (7.3 % vs 5.7%, respectively; p=0.04). A double FCM analysis on fresh and f ixed urine was also performed in 16 cases. In this subgroup, the perce ntage of evaluable histograms from fixed urine specimens was slightly higher than that from fresh specimens. Aneuploid cases were found only in the fixed urine samples but the CVs from fresh and fixed cell susp ensions did not differ. The absence of inflammatory cells with cytolog ical analysis of the same samples was associated with low percentages of FCM evaluability and higher CVs. The use of fixed samples improves the quality of FCM DNA analysis permitting its use for screening progr ams.