Western blotting is a laboratory technique used to detect a specific protein in a blood or tissue sample. The method involves using gel electrophoresis to separate the sample's proteins. The separated proteins are transferred out of the gel to the surface of a membrane. The membrane is exposed to an antibody specific to the target protein. Binding of the antibody is detected using a radioactive or chemical tag. A western blot is sometimes used to diagnose disease.
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Western blot. In the laboratory we often want to measure whether a specific protein is expressed in a sample. We can do this by taking the material from the sample and running it on a gel, and then transferring the resolved proteins onto a special piece of membrane--of paper, if you will--and then probe that paper with an antibody to the specific protein of interest. Because the antibody is labeled with a molecule that we can then visualize, we can ask whether the protein of interest is expressed in this sample and have an idea of how abundant it is, as well as understanding what size the protein is.
Lawrence C. Brody, Ph.D.
Chief & Senior Investigator, Genome Technology Branch; Head, Molecular Pathogenesis Section
Dr. Brody investigates the genetics of breast cancer and neural tube defects. As chief of the NHGRI Genome Technology Branch's Molecular Pathogenesis section, he is interested in studying genetic mutations that lead to perturbations in normal metabolic pathways and cause disorders such as cancer and birth defects. His laboratory investigates mutations in two breast cancer-linked genes, breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). Dr. Brody's laboratory was among the first to report that women carrying BRCA1 or BRCA2 mutations have a higher risk of developing both breast and ovarian cancer than women without such mutations.