Tissue Suspensions for Estimations of Radioactivity

Abstract

THE biologist has frequently to devise an appropriate method for the estimation in a liquid counter of radioactive substances contained in tissues. It is desirable that the technique should be both simple and rapid, and the final fluid medium either a solution of the substance or at least a fine, stable, homogeneous suspension of the total tissue which permits dilution and the removal of representative samples. Coarse suspensions tend to produce erratic counting-rates, due, in part, to drifting of the suspended material into zones of reduced tube efficiency ; this can often be verified by shaking such a suspension in the counter after particles have been allowed to settle. In the case of such elements as the halogens, preparation from the tissues of a solution containing the radioactive compound becomes a tedious process if loss is to be avoided, and in these cases a suspension appears satisfactory.