Electrophoretic mobility profiles of mouse leukemias: I. Electrophoresis of normal mouse thymus and lymph node cell populations.

Anodic electrophoretic mobility of thymocytes and lymph node cells from random-bred ICR Swiss mice was examined. Three cell populations were identified which differed in their surface charge as reflected in their distinct mean AEM and in their time of appearance during the course of life. The first electrophoretically slow-moving population with a mean AEM of 0.97 microns sec-1 V-1 cm was detected in the early postnatal period. In the first month after birth, the first population was replaced by a second, slower-moving population with a mean AEM of 0.83 microns sec-1 V-1 cm. In the second month after birth, a third, fast-moving population with a mean AEM value of 1.24 microns sec-1 V-1 cm appeared in addition to the second cell population. The third population constituted only a minority of thymus cells and continued to be present, as well as the second cell population, up to two years of age. Lymph node cells of ICR mice showed a typical bimodal electrophoretic distribution; fast LNC displayed a mean AEM of 1.18 microns sec-1 V-1 cm whereas slow LNC that of 0.76 microns sec-1 V-1 cm. The percentage of cells in the fast- and slow-moving LNC subpopulations was similar to the expected percentage of T and B LNC. Fractionation of the ICR LNC on nylon wool columns revealed that the majority of the fast-moving LNC corresponded to the nonadherent Thy 1.2+ lymphocytes and the majority of the slow-moving LNC to the nylon wool-adherent sIg+ lymphocytes.