The Protein Man's Blog | A Discussion of Protein Research

Dialysis is a solution-based separation technique used to facilitate the removal of small, unwanted compounds from macromolecules such as proteins, DNA, or polysaccharides through a semi-permeable membrane using the principle of selective diffusion. Although there are a lot of factors that affect the dialysis rate, the semi-permeable membrane is the single most important factor that can determine the success of the process.

After the protein bands have been separated by electrophoresis, researchers perform a dye-binding or color-producing chemical reaction to visualize the proteins embedded within the pores of the polyacrylamide gel matrix. Some of the most popular in-gel detection methods include staining with Coomassie dye, metallic silver, and zinc.

The bicinchroninic acid (BCA) assay, also known as the Smith assay, is a biochemical assay used to determine the total concentration of protein in a solution. Due to its ability to provide accurate determination of protein concentration and its compatibility with most protein sample types, protein laboratories around the world prefer the BCA assay over any other detergent-compatible assays.

We recently reviewed the advantages of total protein membrane stains as a loading control for Western blotting and demonstrated how they were an improvement on routinely used housekeeping genes.

What's best? Housekeeping genes or total protein for Western blot loading controls