Application of flow cytochemistry to the evaluation of HL-60 differentiation

The application of flow cytochemistry to the analysis of previously unreported differentiation-related functions, was investigated in HL-60 cells. After 72 and 96 h of continuous RA-exposure mean peroxidase index and percentage of large unstained cells were significantly less than in time-related control cultures. Percentage neutrophils were significantly increased in induction cultures. Although total cell number increased with time in both control and induction cultures, the increase was less in induction cultures. These findings are consistent with the differentiation-associated growth limitation and with the decreased myeloperoxidase activity reported in RA-treated cultures in other studies. We propose that in the context of RA-induced HL-60 maturation, flow cytochemistry could become a useful adjunct to conventional functional differentiation assessment.