An adapter or adaptor in

genetic engineering Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genet ...

is a short, chemically synthesized, double-stranded

oligonucleotide Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, Recombinant DNA, research, and Forensic DNA, forensics. Commonly made in the laboratory by Oligonucleotide synthesis, solid-phase ...

that can be ligated to the ends of other DNA or RNA molecules. Double stranded adapters are different from linkers in that they contain one blunt end and one sticky end. For instance, a double stranded

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

adapter can be used to link the ends of two other DNA molecules (i.e., ends that do not have "sticky ends", that is complementary protruding single strands by themselves). It may be used to add

sticky ends DNA ends refer to the properties of the ends of linear DNA molecules, which in molecular biology are described as "sticky" or "blunt" based on the shape of the complementary strands at the terminus. In sticky ends, one strand is longer than the o ...

cDNA In genetics, complementary DNA (cDNA) is DNA that was reverse transcribed (via reverse transcriptase) from an RNA (e.g., messenger RNA or microRNA). cDNA exists in both single-stranded and double-stranded forms and in both natural and engin ...

allowing it to be ligated into the

plasmid A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and ...

much more efficiently. Two adapters could base pair to each other to form dimers.

Types of Adapters

A conversion adapter is used to join a DNA insert cut with one

restriction enzyme A restriction enzyme, restriction endonuclease, REase, ENase or'' restrictase '' is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class o ...

, say EcoRl, with a vector opened with another enzyme, Bam Hl. This adapter can be used to convert the cohesive end produced by Bam Hl to one produced by Eco Rl or vice versa. One of its applications is ligating cDNA into a plasmid or other vectors instead of using Terminal deoxynucleotide Transferase enzyme to add poly A to the cDNA fragment. NGS adapters are short ~80 BP fragments that bind to DNA to aid in amplification during library preparation and are also useful to bind DNA to the flow cell during sequencing. These adapters are made up of three parts that flank the DNA sequence of interest. There is the flow cell binding sequence, the primer binding site, and also tagged barcoded regions to allow pooled sequencing.

References

Genetic engineering {{Bioengineering-stub