Automated staining of bone marrow and peripheral blood by a modified Wright's technic

A Wright's stain provided for the automatic staining of routine peripheral blood smears is recommended for use in the Hematrak instrument. This stain at a pH range of 6.5-7.15 shows a dull and bluish coloration of erythrocytes, a finding not readily acceptable for visual microscopy of cell morphology or for photomicroscopy. In order to achieve a desirable erythrocyte color, but still retain the staining intensity of leukocyte chromatin, a two-stage staining method was devised. This involves the use of a mixture of Eosin y and a buffered Wright's solution to secondarily stain Wright-stained smears. This modification of Wright's technic offers a stain of high quality for both bone marrow and peripheral blood films with the advantage of little or no day-to-day variability. In comparison to the frequently advocated dual staining methods, it is cheap and easy to automate. The total staining time for peripheral blood films is about 12 minutes and about 20 minutes for bone marrow smears.