AAT Bioquest

What are the differences between PCR and DNA replication?

Posted August 11, 2022


PCR and DNA replication are two processes responsible for DNA synthesis. These are the key differences between the two processes:

Basic of ComparisonPCRDNA Replication
DefinitionIs a laboratory process used to make many copies of a target DNA region Is a biological process of producing two identical DNA replicas from one original DNA molecule
OccurenceIs an in vitro process that occurs inside a test tubeIs an in vivo process that occurs inside living cells 
ObjectTo generate many copies of a single DNA fragmentTo copy the entire genome at once 
Steps involvedDenaturation, primer annealing, and strand extensionInitiation, elongation, and termination
Temperature at which the process occursOccurs at three different temperatures inside a machineOccurs at body temperature within the body of living organism
Polymerizing enzymeUses thermophilic DNA polymerase such as Taq polymerase, which operates at high temperatures of 72 °C but has no proofreading ability Uses DNA polymerase, which operates at physiological temperature of 37 °C and has proofreading and repair abilities
Primers usedUses DNA primersUses RNA primers synthesized by RNA primase
Denaturing of the Double-StrandsDouble strands are separated by applying a high temperature Double strands are separated by the enzyme DNA helicase
Continuity and speed of synthesisDiscontinuous process which proceeds through 30-40 cycles at a speed of 1-4 kb/minContinuous process, which proceeds at a speed of 1 kb/s
Complexity of processSimple process for in vitro DNA synthesis Complex process that is dependent on a well-defined, complex set of enzymes and co-factors
Accuracy/Error rateError rate of Taq polymerase in PCR is 1 in 9000 basesError rate of DNA polymerase in DNA replication is 1 in 100,000 bases
Additional resources

Design and fabrication of portable continuous flow PCR microfluidic chip for DNA replication

Polymerase Chain Reaction (PCR)

Helixyte™ Green Fluorimetric dsDNA Quantitation Kit *Optimized for Broad Dynamic Range*