Hematology stains aid in the determination of cell count and types in blood/bone marrow by color morphology and structural characteristics. Most stains are differential, or discriminate into what they will stain by the simple principle of “opposites attract”. The positively charged Azure B is attracted to (-) charged phosphate groups of DNA and proteins that have negative charge at physiological pH and stains dark blue. The negatively charged acidic Eosin is attracted to (+) charged proteins whose isoelectric point is above physiological pH.Volu-sol has optimized the traditional stains of Wright and Wright Giemsa to give the best differential stain pattern and quick differentiation of cell types. Solutions for manual staining and solutions for many of the popular automated stainers are also available. Additionally, Volu-sol has pioneered rapid staining formulations, Stat and Statim, to give stain times as fast as 15 seconds. New Methylene Blue N (reticulocyte stain) , Alcoholic Giemsa (deeper penetrating) and the fast and easy Dip Stain are also in stock. Automated stainers have taken over the manual dip staining procedure allowing for a more consistent timed staining, no mess to hassle with, and the ability to multi-task. Unfortunately many automated stainers are quite expensive and make it impractical to own. Volu-sol has engineered the Definitive®, a simple easy to use automated stainer at a reasonable price.