How does PCR work?

PCR stands for polymerase chain reaction. It is a technique used very commonly in molecular biology. It is a way of replicating one strand of DNA into many copies that can then be studied. The components needed in the reaction vessel are:1. the strand of DNA to be replicated2. primers - short strands of RNA needed to begin the replication3. polymerase - the enzyme needed to add the nucleotides onto the DNA chain4. nucleotides - the building blocks of DNAThe reaction takes place in a machine called a thermal cycler, which alters the temperature for each stage of the reactions. This is the sequence of events:1. 95° - the DNA strands separate (denature)2. 55° - the primers bind to the complementary DNA (annealing) 3. 72° - the polymerase adds on nucleotides, copying the DNA strandThe cycle is then repeated, and the amount of DNA doubles each complete cycle. 

AR
Answered by Alex R. Biology tutor

5157 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Describe the chemical composition of phospholipids and how they form cell membranes? (10 marks)


Explain how a mutation in the gene coding for an enzyme could lead to the production of a non-functional enzyme.


How can natural selection create two different species from one species?


What are some of the non-specific, first-line immune defences in humans?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences