Disulfides and Thiols

Disulfides, thiols, and DTPA (diethylenetriaminepentaacetic acid) are important tools in oligonucleotide modification, allowing for diverse conjugation strategies.

Disulfide bonds, such as the internal disulfide (C6), can serve as redox-sensitive linkers within the oligo, allowing for controlled release in reductive environments, which is beneficial for drug delivery and responsive assays.

Thiol-modified oligos are typically synthesized with protected disulfide bonds that can be reduced to generate reactive thiol groups. These thiols, typically introduced at the 5′ or 3′ ends, form stable covalent bonds with gold surfaces, maleimides, and other thiol-reactive molecules, making them ideal for bioconjugation.

DTPA, a disulfide-containing modifier, can be incorporated at any position within an oligonucleotide, providing two thiol groups per insertion. This modification enhances the stability of oligonucleotide attachment to surfaces and improves binding efficiency compared to conventional thiol modifiers. DTPA-modified oligonucleotides also exhibit superior binding to gold or silver electrodes and nanostructures, expanding their potential use in biomedical and diagnostic applications.

The combination of these modifications allows the creation of multifunctional oligonucleotides for various applications.

* For use in research only, proprietary to FRIZ Biochem GmbH

** It is recommended that thiol-modified oligos are ordered lyophilized (and aliquoted), as free, dissolved thiols will slowly react back to their disulfide form.