As a part of our fundamental studies on paper electrophoresis we here present our views regarding selection of the two methods of paper electrophoresis, the Grassmann and the Flynn method. The filter paper used was Whatman No. 1, the stain, Amido Black 10 B.
Ten essentially normal human sera were used, and the results from both methods were almost identical, although differing in minor details. It is these minor differences that we wish to consider here.
(1) With the electrophoretic time being the same for both methods, the length of the electrophoretic migration was longer for the Grassmann method than for the Flynn method. This may be due to the movement of the buffer toward the center of the paper, as a result of the evaporation from the surface of the paper.
(2) The position of γ-globulin with the Flynn method was always on the negative side of the line of origin (electroosmosis), but with the Grassmann method it was consistently on the positive side. This, also, we consider is due to the flow of the buffer to compensate the evaporation loss.
(3) The protein adsorbed at the line of origin was more marked for the Flynn method than for the Grassmann method. We are now considering a way to eliminate this defect in the Flynn method. In order to observe the tailing of the albumin, therefore, the Grassmann method is more convenient.
(4) The reproducibility of both methods, as compared to free electrophoresis was not very good, owing to the evaporation from the paper and also to the sagging of the paper in the Grassmann method.
(5) From the above it is concluded that although the Grassmann method is more popularly used, the Flynn method when properly handled is far from being inferior to the former method.