O S Markovic | PubMed Health

PubMed1978

Device for quantitative cytochemistry: a computerized scanning microdensitometer 'grain counter'.

A computerized scanning microdensitometer and autoradiographic grain counter was able to provide quantitative data on the cytochemical final reaction product formed within a single cell and also quantitate the kinetics of its formation. Optical density and area measurements were performed on hundreds of leukocytes from slides previously stained to demonstrate any one of a variety of reactions. These included cellular glycogen, lipids, peroxidase, esterases, alkaline phosphatase, and acid phosphatase. In addition to these slide studies, chamber studies with an adapted Dvorak-Stotler Chamber allowed the measurement of enzyme kinetics within single cells.

Autoradiography↗

PubMed1977

Megakaryocyte maturation indicated by methanol inhibition of an acid phosphatase shared by magakaryocytes and platelets.

Optimal conditions necessary for the cytochemical demonstration of megakaryocyte (Mk) and platelet acid phosphatase (AP) were determined. Methanol, a constituent of fixatives commonly used in AP cytochemistry, was found to inhibit MkAP, and the degree of inhibition varied with Mk maturity. Immature Mk contained predominantly methanol-resistant AP, and mature Mk, predominantly methanol-sensitive AP. Platelets contained methanol-sensitive AP similar to mature Mk, suggesting that this enzyme provides an index of platelet formation by Mk. Soluble platelet AP showed three bands on polyacrylamide gel electrophoresis, visualized by the same reactions applied cytochemically. Two bands, accounting for 98% of the platelet AP activity, were slow moving and methanol sensitive; and one fast moving band accounting for 2% of activity was methanol resistant. Measurement of Mk and platelet AP isoenzymes may prove to have applications in evaluating Mk function.

Acid Phosphatase↗