AAT Bioquest

What are the differences between linear and circular DNA?

Posted March 25, 2022


Linear and circular DNA are two types of DNA with different structures. Both forms are widely used in molecular biological and genetic engineering studies. While they have a number of similarities between them, there are also several differences.

Basis of DifferentiationLinear DNACircular DNA
StructureHas an open conformation with two free ends, one on each side of the DNA moleculeHas a closed conformation with no ends
DNA SizeLargeSmall
OccurrenceOccurs exclusively inside the nucleusOccurs in the cytoplasm or inside organelles
OrganizationUndergoes tight coiling and dense packing inside the nucleusDoes not undergo packing
Type of OrganismsFound in the nucleus of eukaryotesFound in prokaryotes and also in mitochondrial and chloroplast DNA
Presence/Absence of TelomeresContains telomeresDoes not contain telomeres
Ease of TranscirptionPresence of linear chromosomes makes it easy to under transcriptionDifficult to transcribe because of torsion strain that occurs during DNA unwinding 
End Replication ProblemsHas to face end replication problemsDoes not undergo end replication problem due to their circular shape
ReplicationIs a complex process with multiple origins of replicationIs a simple process with a single origin of replication and unidirectional manner
Occurrence in PlasmidsSome plasmids are linearSupercoiled plasmid DNA is circular
Additional resources

Distinction between supercoiled and linear DNA in transverse agarose pore gradient gel electrophoresis

Portelite™ Fluorimetric DNA Quantitation Kit with Broad Dynamic Range