Polymerase chain reaction (PCR)

Definition

Polymerase chain reaction (PCR) is a technique used to amplify small segments of DNA, generating millions of copies of a specific DNA sequence. It is essential for various applications in genetic engineering and biotechnology.

5 Must Know Facts For Your Next Test

1. PCR requires the use of a DNA polymerase enzyme that can withstand high temperatures, commonly Taq polymerase.
2. The process involves three main steps: denaturation, annealing, and extension.
3. Denaturation occurs at around 94-98°C to separate the DNA strands.
4. Annealing happens at lower temperatures (50-65°C) to allow primers to attach to the DNA template.
5. Extension takes place at around 72°C where the DNA polymerase synthesizes new strands of DNA.

Review Questions

• What are the three main steps involved in PCR?
• Why is Taq polymerase used in PCR instead of other types of DNA polymerases?
• At what temperature does the denaturation step typically occur during PCR?

Related terms

Genetic Engineering: The direct manipulation of an organism's genes using biotechnology.

DNA Polymerase: An enzyme that synthesizes new strands of DNA complementary to the target sequence.

Primer: A short strand of RNA or DNA that serves as a starting point for DNA synthesis during PCR.