What is the primary purpose of Western blotting?

Western blotting is a widely used analytical technique primarily designed to detect specific proteins in a sample. The process involves several key steps, starting with the separation of proteins by gel electrophoresis based on their size. Once separated, the proteins are transferred from the gel to a membrane, usually made of nitrocellulose or PVDF.

Following this transfer, the membrane is incubated with antibodies that specifically bind to the target protein of interest. This step is critical because the use of antibodies allows for the selective identification of proteins, even when they are present in small amounts within complex mixtures. After binding, the presence of the target protein is visualized using various detection methods, often involving secondary antibodies linked to enzymes or fluorescent dyes that generate a signal detectable by imaging systems.

This makes Western blotting a powerful tool for applications such as confirming the presence of a protein in a sample, quantifying protein levels, and studying protein modifications. Other techniques mentioned, such as analyzing DNA sequences or measuring molecular weights, serve different purposes and employ different methodologies, which emphasizes the unique position of Western blotting within protein analysis.