Method for identification of the most abundant oligonucleotide species in a library of oligonucleotides

Abstract

A method for identification of the most abundant oligonucleotide species in a library of oligonucleotides comprising more than 10oligonucleotide species, wherein the oligonucleotides of the library of oligonucleotides are not inherently capable of exponential amplification by PCR and include a coding sequence, which is characteristic of one oligonucleotide specie of the library of oligonucleotides and only one fixed sequence, which is present in a plurality of oligonucleotide species of the library of oligonucleotides, said fixed sequence being located on a 5' side of the coding sequence, and wherein the method comprises specifically amplifying the sequence of a hybridised oligonucleotide species using the steps of: incubating the library of oligonucleotides under conditions of hybridization such as to allow complementary coding sequences to hybridize and form hybridized oligonucleotide species; extending a 3′ end of one or more of the hybridised oligonucleotide species, having only one fixed sequence, to provide extended sequences having an extended region, such that the extended region generates a second fixed sequence thereby forming extended sequences having two fixed sequences; amplifying extended sequences comprising two fixed sequences using PCR to provide amplified sequences, and optionally identifying an identity of the amplified sequences thereby revealing an identity of the hybridised oligonucleotide species in the step of incubating. The library of oligonucleotides is selected from the group of a library of encoded molecules, a library of aptamers, a library of reporter sequences derived from a library of encoded molecules, and a library of aptamers.