A MICROMETHOD FOR DETERMINATION OF THE ABSOLUTE BLOOD VOLUME, WITH DATA UPON THE BLOOD VOLUME OF THE GUINEA PIG, WHITE RAT, RABBIT AND CAT

Abstract

A method for determining blood volume after injection of vital red is described. This method utilizes heparinized blood collected in capillary tubes in amounts not greater than 0.01 cc. After centrifugalization the relative cell and plasma volumes in these tubes are measured and the dye concentration in the plasma read against a previously prepared series of tubes containing known mixtures of dye in plasma. The small amount of blood withdrawn enables one to measure blood volume in animals of the size of frogs and renders it possible to make repeated determinations in small animals. It is also possible to withdraw many specimens from different parts of the body and so determine the distribution of the dye and the true "mixing time.".