Patent ID: 8193336

Claim:
A method for the synthesis of oligonucleotides comprising the steps of: a) contacting an oligonucleotide with a solution comprising a carboxylic acid precursor selected from the group consisting of acetic acids, haloacetic acids, and mixtures thereof; wherein a terminus of the oligonucleotide is protected with an acid-labile protecting group; and wherein a carboxyl group of the acid precursor is protected with a photolabile protecting group; b) exposing the solution to a radiation source sufficient to cause deprotection of the carboxylic acid precursor to provide an acid compound for removing the acid-labile terminal protecting group of the oligonucleotide; c) adding a nucleotide subunit to the deprotected terminus of the oligonucleotide; wherein a terminus of the added subunit is also protected with an acid-labile protecting group.