Difference between Oligonucleotide and Polynucleotide


They are small and similar molecules of RNA or DNA. Oligonucleotides are naturally found as microRNA (22 nucleotides). These short nucleic acids can also be artificially made and are used for DNA sequencing, PCR, molecular cloning, etc. They readily bind to their complementary oligonucleotides in a sequence-specific manner.

An oligonucleotide made of 6 nucleotides is called a hexamer. Likewise, the ones with 25 nucleotides are called 25-mer.


All organisms have naturally occurring polynucleotide. A polynucleotide is made up of a large number of nucleotide monomers. They can also be used in DNA sequencing and PCR techniques. Moreover, oligonucleotides and other small nucleotide chains can be used to make artificial polynucleotides. The new nucleotides are added, and the polymerase enzyme is used to extend the polynucleotide chain.

Usually, a polynucleotide is made of 13 or more monomers of nucleotide. These monomers are covalently bonded.

Difference between Oligonucleotide and Polynucleotide




They are short nucleotide monomers of RNA or DNA.

They are comparatively large nucleotides that have 13 or more monomer units.


They are used in a variety of biological techniques, such as probing, PCR, molecular cloning, DNA sequencing, etc. They also play a vital role in antisense therapy.

Polynucleotides are made of oligonucleotides or other small nucleotide chains. They are mostly used in PCR and DNA sequencing.

Also Refer: Difference between Deoxyribose and Ribose

Frequently Asked Questions


What is a nucleotide?

A nucleoside is composed of a nucleobase (A, T, G, C, U) and a 5-carbon sugar. This nucleoside, along with a phosphate group, is termed nucleotides. These nucleotides are the monomeric units that make RNA and DNA.


What are biopolymers?

They are naturally occurring polymers seen in living cells. They are composed of monomeric units of molecules that are covalently attached. These molecules can be carbohydrates, proteins or nucleotides. Examples of biopolymers – Polysaccharides, Polypeptides and Polynucleotides.

Also Read: Polynucleotide Chain

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