What is Western blot?
[[File:Anti-lipoic acid immunoblot.png|thumb|A complete Western blot that used [[lipoic acid]] to show the proteins. The ladder is on the left. The test proteins are all between 37 and 50 kiloDaltons in size.]] The '''western blot''' is a scientific process. It is a test. Western blotting is also called '''immunoblotting'''. Scientists use Western blots to look at proteins. A Western blot can show how big a protein is. Sometimes a Western blot can show how much of the protein is there.<ref name=Nat>{{cite web|publisher=Nature Education|url=https://www.nature.com/scitable/definition/western-blot-288/|accessdate=September 21, 2022|title=Western blot}}</ref><ref name=TTT>{{cite journal|title=Western Blot: Technique, Theory, and Trouble Shooting|author1=Tahrin Mahmood |author2=Ping-Chang Yang|journal=N Am J Med Sci. |year=2012 |volume= 4|issue=9|pages= 429–434|doi= 10.4103/1947-2714.100998|doi-access=free |pmid=23050259 |pmc=3456489 }}</ref> Scientists studying proteins do Western blots more than any other test. ==Test== A Western blot is one kind of [[gel electrophoresis]].<ref name=TTT /> That means the scientists make a gel in the shape of a rectangle. They put [[electrode]]s on two sides of the gel to make electricity. The electricity makes the proteins move from one side of the gel to the other. One end of the gel has a positive electric charge. The other end has a negative electric charge. Most proteins have a negative charge. So the scientists put the proteins on the negative side of the gel. They put them in neat rows so they can see which sample is which. In one row, the scientist puts a mixture of proteins that they already know. This mixture is called a ladder. Then the scientist turns on the electrodes to make a charge. This can be 60[[volt|V]]. The proteins have a negative charge, so they move toward the positive side of the gel as if they are running a race. The scientist or technician waits for some time. This can be 90 minutes. Then the scientist turns off the electrodes so t