Custom DNA Oligos
Whether your application requires amine modifiers for attachment or biotin for detection assays, we are prepared to meet your needs.
Sbi 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
Most modifications are available at the 0.05, 0.2, and 1.0 µmole scale. Please call for large scale projects.
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.
Contact your local Sigma office for pricing and availability.
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.
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.