Polymerase Chain Reaction (PCR)

Question 1

PCR

How it works?

Answer 1

• uses heat to separate double stranded DNA
• two separate strands used as templates for new strands
• new strand built with special polymerase that can withstand high heat (taq polymerase), needs primer to begin
• temp decreased so primers can anneal to opposite strands
• temp increased for specialized polymerase to work
• process repeats

Question 2

PCR

Uses?

Answer 2

Forensics- only need one cell or fragment of cell that contains some genetic info

Medical diagnosis- early detection of HIV before antibodies present

Genetic research- fossil remains can contain enough genetic info to tell us two species are related

Question 3

PCR?

Answer 3

• Amplification of a DNA sequence by repeated cycles of strand separation and replication
• requires a short time
• allows exponential growth of desired DNA fragment
• old method used bacterial and plasmid cell cloning
• PCR is closely related to DNA replication that occurs in nucleus before cell division