Purified azure B as a reticulocyte stain

Abstract

A comparison was made between reticulocyte preparations stained with purified azure B and with several commercially available batches of brilliant cresyl blue and new methylene blue. Marked variations were observed in the composition and staining performances of the various batches of the 2 commercially available dyes. Although there were no significant differences in reticulocyte counts obtained with these 2 dyes, varying amounts of an extraneous, particulate dye deposit were present in these preparations, making accurate counting both tedious and time-consuming. Purified azure B, on the other hand, gave reproducibly stained, deposit-free preparations. Reticulocyte counts obtained from azure B preparations correlated almost exactly with those determined using new methylene blue. Purified azure B is therefore recommended as a convenient reticulocyte stain for routine use.