Question

1. describe western blotting. √ 4

Explanation:

Western blotting is a laboratory technique used to detect specific proteins in a sample. First, proteins are separated by size via gel electrophoresis. They are then transferred (blotted) onto a solid membrane. Next, the membrane is incubated with primary antibodies that bind to the target protein, followed by secondary antibodies that bind to the primary antibodies. Finally, a detectable signal (e.g., chemiluminescence) is generated to visualize the target protein's location and relative amount.

Answer:

Western blotting is a molecular biology technique used to identify and quantify specific proteins in a biological sample. The process involves four key steps:

1. Gel Electrophoresis: Proteins are separated by molecular weight using SDS-PAGE (Sodium Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis).
2. Transfer: The separated proteins are transferred (blotted) from the gel onto a nitrocellulose or PVDF membrane.
3. Immunodetection: The membrane is incubated with a primary antibody that specifically binds to the target protein, then a secondary antibody (linked to a reporter molecule) that binds to the primary antibody.
4. Signal Visualization: The reporter molecule (e.g., an enzyme that produces light or a colored product) generates a signal that reveals the position and relative abundance of the target protein.