Can you use serum to perform a western blot?

Answer 1

You can do a western blot using plasma as samples, but you have to keep in mind that there are many factors that need to be considered. My area of research is looking for brain proteins in the blood of stroke patients. So far, I have had many difficulties working with plasma.

The major problems seemed to be non-specific binding and protein overload.

Non-specific binding: Both my primary and secondary antibodies seem to bind non-specifically to proteins other than the protein of interest. My primary antibody seemed to pick up proteins abundant in the plasma such as albumin.

My secondary antibody seemed to pick up human immunoglobulin molecules. So, if you are not isolating out your protein of interest from the plasma to run a western blot, it may be a good idea to first run different dilutions of the primary and the secondary antibody to determine the optimal concentrations to be used.

Also, the other problem that I was facing was protein overload, or what I interpreted as a protein overload. When I ran westerns using 2 microlitres of human plasma, the dye front was smeary and there seemed to be precipitates left in the well of the gel. So, if required, maybe run a protein concentration assay to determine the optimal plasma volume to load as well?

I hope that helps.

Answer 2

Western blot is an analytical used to detect proteins from a lysate or any other sample.
Yes you can use any protein sample to western blot. Only problem with serum is, it contains tons of antibodies, so this will give a large 25kDa and 50kDa band that may mask you protein you want to detect.