1. A new modification of existing methods has been described for the separation of leukocytes from whole blood which provides a procedure for the rapid isolation of uninjured cells suitable for the study of oxidative phosphorylations.
2. This method has been employed in a study of the relative efficiency and yield of oxidative-linked phosphorylations mediated by normal and leukemic or immature leukocytes. The maximum aerobic phosphorylating capacity was exhibited by chronic lymphocytic leukemic leukocytes, followed in decreasing order of activity by acute monocytic leukemic leukocytes and chronic myelocytic leukemic leukocytes. Oxidative phosphorylation was not demonstrated with normal leukocytes.
3. Results of this study suggest that expression of leukocyte metabolic data on a unit nitrogen basis more accurately reflect the morphologically obvious size differences among the various leukocytes than presentation of data on a unit cell basis.
4. The aerobic phosphorylations mediated by leukemic leukocytes were found to be dependent upon substrate addition and were depressed by low levels of dinitrophenol. Under the experimental conditions employed in this study, glucose-6-phosphate was formed in stoicheiometric amounts. These results indicate that leukemic leukocytes are capable of the aerobic esterification of inorganic phosphate accompanying the oxidation of selected Kreb's cycle intermediates.