Question

To detect specific proteins in a sample we use:

• A. Eastern Blotting
• B. Foot printing
• C. Northern Blotting
• D. Western Blotting

Hint:

Mnemonic to remember blotting techniques:
S N O W
D R O P
S = Southern (D = D), N = Northern (R = R), W = Western (P = Protein).

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question asks for the standard laboratory blotting technique used specifically for identifying and detecting target protein molecules in a biological sample.

Step 2: Key Formula or Approach:
Blotting techniques separate biological macromolecules based on size via gel electrophoresis and transfer them to a membrane for detection using specific probes:

• Southern Blotting $\to$ D detection

• Northern Blotting $\to$ R detection

• Western Blotting $\to$ Protein detection

Step 3: Detailed Explation:

• Western Blotting Protocol: Proteins are first separated according to molecular weight using Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE).

• Transfer to Membrane: The separated protein bands are electrophoretically transferred onto a carrier membrane, typically nitrocellulose or polyvinylidene difluoride (PVDF).

• Immunodetection: The membrane is blocked to prevent non-specific binding and probed with a primary antibody specific to the target protein, followed by a secondary antibody conjugated to an enzyme (e.g., HRP or AP) or fluorophore for visualization.

• Alysis of Other Options:

• Eastern Blotting: Used to detect post-translatiol modifications of proteins such as carbohydrate or lipid moieties.

• Footprinting (D Footprinting): Used to identify D sequences bound by specific D-binding proteins.

• Northern Blotting: Used to alyze gene expression by detecting target R sequences.

Step 4: Fil Answer:
Western blotting is the standard method used to detect and quantify target proteins within a protein mixture.