Two new techniques for measuring the electrophoretic mobility of red cells and ghosts are described. In the first, the mobilities are measured in a vertical electrophoresis cell in which they are seen by phase contrast. This enables mobilities to be measured even when ghosts contain so little Hb as to be invisible with the ordinary microscope. The second method uses an Antweiler electrophoresis apparatus to give measurements of the mobility of moving boundaries between columns of red cells or ghosts and the suspension medium.

It can be shown by these methods that the usual statement that the mobilities of ghosts are the same as those of the red cells is an over-simplification. The mobilities, under comparable conditions, are more generally dependent on the method used to prepare the ghosts and on the time which has elapsed after lysis.

The statement that the isoelectric point of watery ghosts is as low as pH 2.0 or even less is confirmed, as is also the general shape of the pH-mobility dependence.

This investigation was carried out under Army Contract No. DA-49-007-MD-458.