A rapid, vital staining procedure for flow cytometric analysis of human reticulocytes

A fluorescent staining procedure based upon thioflavin T is described. This dye permits rapid, vital, nonprecipitative staining of human reticulocytes. Flow cytometric analysis of thioflavin T stained whole blood specimens results in reticulocyte counts that correlate well with new methylene blue reticulocyte counts and give coefficients of variation approaching the theoretical limit. The shape of the fluorescence histogram is qualitatively similar to the reticulocyte age profile. Paired new methylene blue and thioflavin T reticulocyte counts are presented with illustrative cases of reticulocyte maturity distributions.