D ring the past ten ears or so, there has been an increasing n mber of p blications describing ario s aspects of oligon cleotide chemistr and the application of oligon cleotides in basic, as ell as applied science. More recentl , ario s oligon cleotide conj gates nthesi ed that are c rrentl being st died for their ha e been s potential diagnostic and therape tic applications. With the introd- tion of ne oligon cleotide conj gates, anal tical methods for the anal sis of these oligon cleotides are also being de eloped and op- mi ed. The present ol me, Protocols for Oligon cleotide Con- gates: S nthesis and Anal tical Techniq es, is designed to bring readers p-to-date on the protocols for the s nthesis of ario s oli- gates and on all the important techniq es for the n cleotide conj nthetic oligon cleotides and their analogs. The s- anal sis of s thetic chemistrof man of these oligon cleotides and their ario s analogs has been co ered in a companion ol me entitledProtocols for Oligon cleotides and Analogs: S nthesis and Properties. The first chapter ofProtocols for Oligon cleotide Conj gates- scribes the protecting gro ps in oligon cleotide s nthesis.