Adsorption of Carbon‐14 Dextran to Human Blood Platelets and Red Blood Cells, in Vitro *

A carboxy‐labeled dextran fraction was incubated with human whole blood. The platelets and erythrocytes were separated by differential centrifugation and washed 6 times with compatible human plasma containing non labeled dextran. After the cells were oxidized by wet combustion, the CO2 was collected in an ionization chamber and the activity was determined with a Vibrating Reed Electrometer. It was found that 2.4 to 15.0 times 103 dextran molecules were associated with each cell. This indicates that much more than interstitial dextran remains with the cells.