The usual manual preparation of single-cell
suspensions from fixed
paraffin-embedded tissue sections for flow cytometric (FCM)
DNA ploidy analysis is a time-consuming, labor-intensive technique that requires 70 minutes to deparaffinize and rehydrate 50 microns sections as the initial step. Manual deparaffinization was compared with two semiautomated methods using an automatic slide stainer with either a 70-minute or 35-minute schedule. Samples from 6 normal tissues and 21
tumors (13 diploid and 8
aneuploid) were prepared using all three methods and analyzed by FCM. The mean cell counts in all samples were over 10(6). The
DNA indices for the three samples prepared from a given tissue showed no significant differences. Using the 70-minute automation schedule, no
aneuploid peaks were lost, and the ratio of G0G1 normal cells to
aneuploid tumor cells was maintained. The automation of deparaffinization can thus provide a significant reduction in the labor need to produce single-cell
suspensions for FCM; it can be especially helpful when handling large numbers of
tumors. At the same time, the automated procedure decreases the exposure to
hazardous chemicals and lowers the chance of losing tissue.