The electrophoresis is the most used technique to separate proteins and usually the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) proposed by Laemmli is the prefered since it can diferentiate large size proteins, but for very low molecular weight proteins such as 3 KDa and below becomes difficult. Thus a modification of the basic Laemmli SDS-PAGE protocol was required to allow for proteins up to 10 KDa to be separated, maintaining good resolution and reproducible results. This work demonstrates how a 18% gel and modifications of the basic Laemmli protocol acrylamide gel let protein samples with 1 KDa and 0.6 KDa be visible and separated.

This is a quite simple but reliable protocol to make very high transformation efficiency yeast competent cells. By express your gene of interest, protein function can be studied in yeast cells.