Sequence identity of the n-1 product of a synthetic oligonucleotide

Abstract

After synthesis and purification of an oligonucleotide, the final product usually contains a low level of n-1 congeneric species. We have sequenced the n-1 population of a 25mer phosphodiester oligonucleotide. The n-1 band was cut from the gel and eluted. Ollgonucleotides were tailed with dA and annealed to a dT-tailed plasmid. The recombinant plasmld was ligated and used to transform competent bacteria. Our results show that the n-1 population was heterogeneous. The frequency of truncated nucleotides at the 3-end was much higher than at the 5′-end of the oligomer. No truncated nucleotides were found in the last four nucleotides at the 5′-end. Our results also show that the chain of oligonucleotides can grow on unreacted sites of a controlled-pore glass support. © 1995 Oxford University Press.