Asymmetric PCR is a variation of
PCR used to preferentially amplify one strand of the original
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 ...
more than the other.
The technique has applications in some types of
sequencing
In genetics and biochemistry, sequencing means to determine the primary structure (sometimes incorrectly called the primary sequence) of an unbranched biopolymer. Sequencing results in a symbolic linear depiction known as a sequence which succ ...
and
hybridization probing where having only one of the two complementary
strands is required.
Methodology
Asymmetric PCR differs from regular PCR by the excessive amount of
primers for a chosen strand. Due to the slow (arithmetic) amplification later in the reaction (after the limiting primer has been used up) extra cycles of PCR are required.
A modification on this process, known as
Linear-After-The-Exponential-PCR (LATE-PCR), uses a limiting primer with a higher
melting temperature than the excess primer to maintain reaction efficiency as the limiting primer concentration decreases mid-reaction.
Applications
Asymmetric PCR can be used to form single stranded DNA from double stranded DNA, which is then used for
DNA sequencing
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, thymine, cytosine, and guanine. The ...
in the
mutagenesis method. Single stranded DNA is also important for
aptamer
Aptamers are oligomers of artificial ssDNA, RNA, Xeno nucleic acid, XNA, or peptide that ligand, bind a specific target molecule, or family of target molecules. They exhibit a range of affinities (Dissociation constant, KD in the pM to μM rang ...
generation.
References
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DNA sequencing