Applications of Vertical Electrophoresis

Determination of Molecular Weight-

Molecular weight of a protein can be determined by plotting relative migration Rf with the log molecular weight of standard protein.

…………Eq (23.1)

The value of the relative migration (Rf) is calculated from the SDS-PAGE. For each protein band, a line is drawn from the middle of the band and then the distance from the lane is measured. A distance for dye front is also measured. The values of relative migration (Rf) and log molecular weight of the standard protein is used to draw the calibration curve to calculate the molecular weight of the unknown sample (Figure 23.1).

Figure 23.1: Determination of molecular weight using SDS-PAGE. (A) SDS-PAGE (B) Determinaion of Rf.