2.4

PCR (Polymerase Chain Reaction)

A technique used to amplify specific regions of DNA, turning a few copies into millions or billions.

Denaturation

The first step in PCR where DNA strands are separated by heating to 95 degrees Celsius to break hydrogen bonds.

Annealing

The second step in PCR where short DNA primers bind to complementary sequences on the DNA at a lower temperature.

Extension

The third step in PCR where DNA polymerase synthesizes new DNA strands starting from the primers.

DNA polymerase

An enzyme used in PCR to synthesize new DNA strands, particularly from thermophilic bacteria for stability under high temperatures.

Gel electrophoresis

A post-PCR analysis technique used to separate DNA fragments based on size, utilizing DNA's negative charge.

Forward primer

One of two sets of primers used in PCR, it binds to one strand of DNA to initiate amplification.

Reverse primer

The second of two primers in PCR, it binds to the opposite strand and helps define the boundaries of the DNA region being amplified.

DNA ladder

A size marker used in gel electrophoresis to estimate the size of PCR products.

Sequencing PCR

A specialized form of PCR that uses chemically modified nucleotides that fluoresce to determine the DNA sequence.