“…Since collagenase is a widely used enzyme for tissue disaggregation, especially in tumor cytogenetics, the presented data will have consequences for the interpretation of results obtained by methods involving the use of this enzyme. Key terms: Solid tumor cytogenetics, DNA flow cytometry, DNA aneuploidy, tissue disaggregation Solid tumor cytogenetics comprises a small but rapidly expanding field of research, A number of reports on the cytogenetics of prostate carcinoma (PC) have indicated several structural chromosome rearrangements, which are thought to be possibly tumor specific (1,7,8,14). However, the majority of the investigated PC specimens (73%) demonstrate a surprising lack of both structural and numerical chromosomal changes, resulting in essentially normal diploid karyotypes (3,8,141.…”