1. In vitro, human erythrocytes free of contaminating white cells and platelets do not oxidize fatty acid in the surrounding medium, either bound to albumin or supplied in buffer as the potassium salt. These results are not influenced by glucose deficiency.
2. White cells and platelets are both capable of oxidizing fatty acid from the surrounding medium—supplied either as the potassium salt in buffer or bound to albumin. Increasing the albumin/fatty acid molar ratio results in a decrease in the quantity of fatty acid oxidized. The amount of fatty acid oxidized is greater if glucose is not added to the medium.