RICHARD-ALLAN SCIENTIFIC COMPANY 3111 Epredia

Hematology stains are typically mixtures of several thiazin dyes in a methanol solvent. Ionic and non-ionic forces are involved in the binding of the dyes. The negatively charged phosphoric acid groups of DNA attract the purple polychromatic cationic dyes to the nuclei. The blue basophilic granules are stained by the polychromatic cationic dyes. Cationic cellular components, such as the erythrocytes and eosinophilic granules, are stained by the red and pink anionic dyes. The buffers used in the staining procedure liberate and activate dye ions allowing them to chemically bond with specific cellular components. When staining blood and bone marrow smears, the pH of the staining solution and/or buffer is a critical factor. The Wright, Wright-Giemsa, Giemsa, May-Grunwald and Jenner stains all rely on a separate buffer solution to control the pH of the reaction, whereas the buffered versions are referred to as “one-step” and have the buffering component already in the staining solution. There are pros and cons to each type of hematology stain although they all contain the thiazin dyes which control the coloration of the nuclear cell components. The single solutions with buffer included generally present more precipitate and the cellular detail is not defined as well as using separate stain and buffer solutions. This kit contains three 500ml bottles of Wright Giemsa stain, pH 6.8 Buffer and a Rinse solution intended to be used as a system per the instructions for use.