Gene Knockout

Gene knockout is the complete elimination of an organism’s gene. The gene is made inoperative, and such organisms are called knockout organisms or knockouts (KO).

Knockouts are used to study gene function and the effect of gene loss on the organism’s functioning. When two genes are knocked out in an organism, it is known as double knockout; similarly, triple knockout and quadruple knockout for three and four gene eliminations.

KOs are useful in the screening of drug development, deficiencies, understanding any biological concept and scanning the entire genome of an organism by constructing libraries.

Gene Knockdown

Gene knockdown is the mechanism where the expression of a gene is reduced by chemical methods or genetic modifications. When the expression of genes is altered by genetic methods, the alteration is temporary, and it is known as a transient knockdown. In this method, an oligonucleotide that is capable of binding to mRNA is allowed to bind with active transcripts. The binding of the oligonucleotide either blocks the transcription, degrades the mRNA transcript, destroys pre-splicing sites or blocks the translation process.

Gene Knockout vs Gene Knockdown

Gene Knockout

Gene Knockdown


Gene knockout is the complete elimination of genes from an organism.

Gene knockdown is the reduction of the expression of a gene in an organism.


It can happen only by genetic engineering techniques.

It can either happen by chemical agents or genetic modification.


Homologous recombination, Zinc fingers, TALENs (Transcription activator-like effector nucleases)

RNAi (RNA interference), CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats)


It is used to study gene function by analysing the effect of the loss of genes on that organism.

It is used to find out the function of a gene that has been already sequenced (reverse genetics), and it is also found useful in developmental biology.

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Frequently Asked Questions

What is the difference between knockout and knockin?

Gene knockout and gene knockin are two techniques that are opposite of each other. While gene knockout is the elimination of a targeted gene, knockin is the insertion of a foreign gene into the organism’s genome.

What is the difference between transgenic animals and knockout animals?

Transgenic animals are the ones that have foreign genes inserted into their genome for biotechnological purposes. On the other hand, knockout animals are the ones that have their genes eliminated from their genome.

What are the advantages of gene knockout technology?

The most significant advantage of gene knockout technology is that it allows us to study the functions and role of genes in different organisms.

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