Frequently asked questions

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How do I order a phosphorothioate modified oligo?

IDT uses a simple notation for phosphorothioate bonds (PS bonds). Insert an asterisk (*) between the bases within your sequence to denote a phosphorothioate chemical modification. The following example has a PS bond between the T and G bases: 5'- TTTTTT*GGGGGG -3'. PS bonds introduced between the last nucleotides at the 5'- or 3'-end of the oligo inhibit exonuclease degradation. Order PS-modified oligos at: