Standardized Azure B as a reticulocyte stain

Standardized (i.e. purified) Azure B (AB), now commercially available, is recommended as the standard dye for reticulocyte staining. AB is compared with the frequently used cationic dye Brilliant Cresyl Blue by visual observation and computer-guided image analysis. The staining performance of the two dyes is similar but, in the interests of laboratory economy, AB is preferable for practical use because, like Eosin Y, it is also present in the standard Romanowsky Giemsa stain.