Availability: DNA or RNA
Scales: 100 nmol-large scale
Purification: HPLC or PAGE
Symbol for ordering: * placed between 2 nucleotides
Figure 1. Phosphorothioate modification.
Preventing nuclease degradation
Phosphorothioate bonds substitute a sulfur atom for one of the non-bridging oxygen atoms in the phosphate backbone of an oligonucleotide. Phosphorothioates are primarily incorporated to prevent nuclease degradation. Substituting a sulfur atom for an oxygen atom renders the internucleotide linkage resistant to both endo- and exonucleases. Placing this modification between nucleotides at either terminus of an oligonucleotide sequence will provide exonuclease protection, while using the modification internally will inhibit endonuclease degradation. To order, place an asterisk (*) between 2 nucleotides, indicating the bond you would like to modify (e.g., A*CTG*ATCG*A).
Other modifications to facilitate your research
See what other modifications are available from IDT. You can find a list of standard modifications we make to oligonucleotides on the Modifications page of our online catalog. And if you don’t find what you are looking for, just send us a request. We often synthesize special, non-catalog requests. Contact us at firstname.lastname@example.org.