Custom Oligos Modifications

We offer over 200 modifications for both DNA and RNA oligonucleotides and probes. We can attach fluorescent dyes to oligos at the 5'-end, 3'-end and internal positions. Our product offering includes common dye modifiers such as 6-FAM™, HEX™, and TET™, as well as exotic modifications.

In addition to standard fluorescent modifications, we have the capabilities to provide Dual-Labeled Probes including Molecular Beacons, LightCycler^® Probes, and Scorpions^® Probes.

• Minimum Yield Guarantees
• Shipping Schedule
• Quality Control

Modification Categories

• Fluorescent
• Attachment
• Binding
• Spacer
• Analog
• Intercalation
• Antisense
• Phosphorothioates

Phosphorothioates (or S-oligos)

Phosphorothioates (or S-oligos) are a variant of normal DNA in which one of the non-bridging oxygens is replaced by sulfur. The sulfurization of the internucleotide bond creates a molecule that is resistant to cellular nuclease degradation. Sulfur bonds can be introduced at the 5’, 3’, or internal positions.

*Guarantees are for 20 mers or longer.  Oligos shorter than 20 bases will have fewer ODs. Microgram amounts are calculated based on a 30 μg/OD value.  If the μg/OD value is less than 30, the reported μg value will be proportionally less. Phosphorothioated yields are 70% of the above stated values. Post-synthesis modifications may yield 50% less than the above stated values.

*Guarantees are for 20 mers or longer. Oligos shorter than 20 bases will have fewer ODs. Microgram amounts are calculated based on a 30 μg/OD value. If the μg/OD value is less than 30, the reported μg value will be proportionally less.

*For complete label license information, please visit sigmaaldrich.com/oligolicenses.