Microturbidimetric determination of erythrocyte osmotic fragility in newborn,weanling and mature rats

A rapid, microturbidimetric method for recording red cell osmotic fragility using a Platelet Aggregometer is described. This method requires only 0.2 ml of whole blood and a fragility curve of 20 points can be determined in less than 1 hr. Measurement of the degree of hemolysis is based on the increasing transparency of the erythrocyte suspension when hemolysis takes place. Erythrocytes of immature animals are osmotically more resistant than those of adults and the change in osmotic resistance is not directly related to the percentage of reticulocytes.