DNA ploidy using paraffin-embedded tissues in urological cancer : 1. basic study

A laboratory study was performed to obtain better DNA analysis by flow cytometry (FCM) with paraffin-embedded tissues using mice transplantable tumor (MTB-2). As potential determinants for DNA measurement, the fixation method of the specimen, the thickness of the sectin, deparaffining agents and isolation methos of cell nuclei were ecamined. Conditions for obtaining DNA histogran with the minimum coefficient of variation (CV) values were as follows. (1) The formalin fixation was better than the alchol fixation. (2) The thickness of section was more than 30μm. (3) Hisco-Clear was better than cylene in deparaffin. (4) The isolation method of cell nuclei was over-night incubation with 0.25% trysin containing spermine. The possibility of obraining better CV calues for clinical specimens was indicated under the above treatment confitions.