Two complementary fluorimetric assays for the determination of aminoquinoline binding and uptake by human erythrocytes in vitro

We provide two simple low-cost and low-tech procedures to measure with good precision and accuracy the binding and internalization into human erythrocytes of chloroquine and other aminoquinolines. The methods are based on the high fluorescence of the quinoline ring and are complementary. Method A evaluates residual drugs in the supernatants of treated erythrocytes, whereas method B quantifies the total uptake by whole cells and the fraction bound to the membranes. Drug uptake is dose dependent and related to the number of erythrocytes. These assays could be useful when studying the cell interaction of quinoline-type compounds not available in the radioactive form.