The increase of electrophoretic mobility and alkaline phosphatase activity are parallel events during B-cell...

B-lymphocyte derived mouse myeloma cells P3X63Ag8U.1 were used to study the change of the negative surface charge density which occurs during a final maturation step of mouse and human B-cells. These cells showed a uniform EM distribution curve as long as they lived within a clone. However, when they grew in suspension at low density, a part of them increased their electrophoretic mobility (EM). Cells with enhanced EM were isolated by free flow electrophoresis. They showed lower proliferation and clone forming activity but higher alkaline phosphatase activity than cells with unchanged low EM. The study suggests that the increase of the EM and of the alkaline phosphatase activity are parallel events associated with B cell progression from the proliferative to the Ig secretion stage.