Dear Lim,

Thank you for your interest in TriLink’s custom oligo synthesis. Thethree thiol linkers you mention differ by the position on the oligonucleotide (5′ or 3′) and the linker length (3 or 6 carbon chain). The structure of the reduced thiol linker can be found on each product page. Thiol modified oligonucleotides are shipped as the protected thiol (for example, C6-S-S-C6, aka disulfide) to avoid dimerization. Prior to use, the disulfide can be reduced using TCEP. Thiol modified oligos can be ordered through OligoBuilder®.

Thiol modified oligos can be direclty linked to a gold surface as described by Li Z, Jin R, Mirkin CA, Letsinger RL. .

Please let us know if you have any additional questions.

Best regards,
Elizabeth