Custom DNA Oligos

Whether your application requires amine modifiers for attachment or biotin for detection assays, we are prepared to meet your needs.

Capabilities

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
  1. 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.