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Custom DNA Oligos
Additional Modifications | ||
Whether your application requires amine modifiers for attachment or biotin for detection assays, we are prepared to meet your needs.
Capabilities
Sigma® can attach oligo modifications at the 5'-end, 3'-end and even internal positions. In addition to fluorescent dyes and dual-labeled probes, our modifications include:
| Description | Position Available | Recommended Purification |
| Amine C3 | 5' | Desalt, RP1, HPLC |
| Amine C6 | 5' | Desalt, RP1, HPLC |
| Amine C12 | 5' | Desalt, RP1, HPLC |
| Amino dT | 5', Internal | Desalt, RP1, HPLC |
| Biotin-TEG | 3', 5', Internal | Desalt, RP1, HPLC |
| Biotin | 5' | Desalt, RP1, HPLC |
| Biotin dT | 3', 5', Internal | Desalt, RP1, HPLC |
| Phosphorylation | 3', 5' | Desalt, PAGE |
| Phosphorothioate (Antisense Oligos) | 3', 5', Internal | Desalt, RP1, HPLC |
| dI | 3', 5', Internal | Desalt, RP1, HPLC |
| dU | 3', 5', Internal | Desalt, RP1, HPLC |
| Spacer 9 | 5', Internal | Desalt, RP1, HPLC |
| Spacer C3 | 3', 5', Internal | Desalt, RP1, HPLC |
| Thiol C6 S-S | 5', Internal | Desalt, RP1, HPLC |
Synthesis Scales
Most modifications are available at the 0.05, 0.2, and 1.0 µmole scale. Please call for large scale projects.
Purification
Desalt or cartridge (RP1) purification is acceptable for most common phosphoramidite modifiers. However, additional purification is strongly recommended for modifiers that require NHS-ester chemistry to conjugate a dye through an amine linker such as Molecular Probes dyes.
Pricing
Contact your local Sigma office for pricing and availability.
Minimum Yield
Due to the chemistry of many modifications, yield will be approximately 40 - 60 % less than a standard oligo. Please see our yield chart for details.
Quality
Every oligo synthesized is strictly controlled for quality by using either MALDI-TOF mass spectrometry or polyacrylamide gel electrophoresis (PAGE) analysis. Final yields are determined using UV absorbance at OD260. In addition, we perform QC methods tailored to specific modifications, such as OD ratio measurement where appropriate.
You will receive a Quality Assurance Certificate that includes quantitated yield, melting temperature, MW and µg/OD with every oligo. You will also receive an additional label for use in your records or on an additional vial.
Shipping Schedule
Expected shipment time for common dye modifiers is 5 working days. More complicated modifications are usually completed within 5 - 7 working days. Visit our shipping schedule for more details.
For additional information, please send your request to ginformation@sial.com
or call us at 1-800-234-5DNA (5362).