EVALUATION OF A CYTOCENTRIFUGE TECHNIQUE EFFECTS ON QUANTITATIVE DETERMINATION OF FEULGEN- DEOXYRIBONUCLEIC ACID AND TOTAL DRY MASS OF HUMAN LEUKEMIC CELLS’

The cytocentrifuge has been used as a tool to obtain preparations from suspension cul-tures suitable for quantitative cytochemical analysis. Three continuous suspension cul-tures of human lymphocytic cells (CCRF-CEM, acute lymphoblastic leukemia; CCRF-RKB, infectious mononucleosis; and EB-3, Burkitt’s lymphoma) and a suspension of mouse inguinal lymph node lymphocytes were examined for quantitative differential ef-fects on cellular dry mass and Feulgen-deoxyribonucleic acid (DNA) contents caused by cytocentrifugation. When using a cytocentrifuge technique which results in a dry prepa-ration, a quantitative loss was observed for cellular dry mass but not for Feulgen-DNA. However, if a medium which prevented bursting, swelling or loss of cellular constituents during cytocentrifugation was used and if the preparation was maintained in the wet state (no air-drying), acceptable preparations for both dry mass and Feulgen-DNA quan-titation can be obtained. These and other observations on centrifugal force, centrifuge time and suspending medium emphasize the importance of specimen preparation when quantitating cell parameters that may themselves be altered by the method of prepara-tion