This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Gene amplification is by 
Select and explain. 
A. Polymerase Chain Reaction, B. Ligase chain reaction, C. DNA hybridization, D. In situ hybridization
A: Polymerase Chain Reaction
Answer: A: Polymerase Chain Reaction 
Explanation: PCR is an in-vitro DNA amplification procedure in which millions of copies of paicular sequence of DNA can be produced within a few hoursRef: DM Vasudevan, 7th edition, page no: 638