Flow-cytometric enumeration of reticulocytes with the new fluorochrome 1,3'-diethyl-4,2'-quinolylthiacyanine (correction of 1',3'-diethyl-4,2'-quinolylthiacyanine)

Several flow-cytometric methods for reticulocyte enumeration in whole blood have been developed, with different degrees of practical use. Recently, a new fluorochrome, 1,3'-diethyl-4,2'-quinolylthiacyanine (corrected) (DEQTC) was proposed in a brief report, as an alternative to thiazole orange for reticulocyte counting. We have evaluated the usefulness of this fluorescent stain by assessing the optimal conditions for the flow-cytometric analysis, and by comparing in double-blind assays the quantitative results of this technique with those obtained by manual counting with brilliant cresyl blue. Our results show that flow cytometry with DEQTC is highly correlated to the manual method (r = 0.95-0.99), supporting the interest of this particular stain and of flow cytometry for routine laboratory work in hematology.