Thiol linkers can be used to form either reversible disulfide bonds or stable thiol ether linkages with
maleimides. Care must be used when working with mercaptan labeled oligos. They will dimerize unless they are stored in a non-oxidizing environment. To avoid dimerization issues we recommend that you take delivery of the protected thiol (disulfide) form. The reduction of the disulfide with TCEP can be done at the same time the maleimide is conjugated.

The purified yields of thiol modified oligonucleotides are often lower than the analogous amino modified oligonucleotide.