Application of long-term collagenase disaggregation for the cytogenetic analysis of human solid tumors.

A method has been elaborated for obtaining chromosome preparations from different histologic types of human solid tumors and applied to 60 cases. Such tumors were mechanically dispersed, washed by settling and transferred into flasks containing collagenase (200 U/ml) in the growth medium. Tumor pieces were dissociated in enzyme for 16 hours to 6 days, depending on tumor consistency. The majority of the tumors (80%) required 16-24 hours of such treatment. After disaggregation, the suspension of cells was washed by settling and then centrifuged. Cells were cultured for 24 hours to 6 days (85% of tumors), treated with a hypotonic solution in situ and then fixed. Of the 60 tumors, 37 (60%) displayed a sufficient number of metaphases for banding analysis. The success rate depends primarily on the type of tumor: 70% for soft tissue sarcomas, 40% for bladder carcinomas, and 40% for renal adenocarcinomas. This procedure is gentle, requires no special equipment and is applicable for the study of the full spectrum of human solid tumors.