Question

Which of the following in vitro technique is used to find Protein-Protein Interaction

• A. Yeast-two hybrid
• B. In-situ hybridization
• C. Fluorescent Radio-recovery after Photobleach (FRAP)
• D. Western Blotting

Hint:

When answering questions about techniques, focus on the primary purpose of each method. Yeast-two hybrid = Protein-Protein Interaction. In situ hybridization = Nucleic Acid Location. Northern/Southern/Western Blot = RNA/DNA/Protein Detection. FRAP = Molecular Mobility.

Answer 1

The Correct Option is A

Step 1: Understanding the Task:
The question requires identifying an "in vitro" technique from a list used to study protein-protein interactions (PPIs). "In vitro" refers to experiments outside a living organism, unlike "in vivo" (within a living organism) and "in situ" (in its original location).
Step 2: Analysis of Options:
1. Yeast-two hybrid (Y2H): Y2H is a common molecular biology technique for discovering protein-protein interactions. It uses the modularity of transcription factors in yeast. Two proteins of interest are fused to separate transcription factor domains. If the proteins interact, they bring the domains together, reconstituting the transcription factor and activating a reporter gene. This occurs inside a living yeast cell, making it an in vivo method. However, among the choices, it's the most direct and well-known method for discovering PPIs. The "in vitro" descriptor may be a question error.
2. In-situ hybridization: This technique detects and localizes specific nucleic acid (DNA or RNA) sequences, not protein interactions.
3. FRAP: This microscopy technique measures the dynamics and mobility of fluorescently labeled molecules within a living cell (in vivo). While it can provide indirect evidence of interactions, it's not a direct PPI detection method.
4. Western Blotting: This technique detects specific proteins in a sample but doesn't directly detect PPIs. It's a detection step in techniques like Co-immunoprecipitation (Co-IP), an in vitro method. However, Western Blotting alone doesn't identify interactions.
Step 3: Conclusion:
The Yeast-two hybrid system is the most direct technique for identifying protein-protein interactions among the options. Although it is an in vivo technique, its significance in PPI discovery makes it the most likely intended answer, assuming the "in vitro" qualifier in the question is an error.