Maleimide modified oligonucleotides are typically used to form conjugates with thiol-labeled moieties, or Diels-Alder cycloaddition products. Maleimide can be incorporate during oligo synthesis using phosphoramidite chemistry at 5' end separated oligo with 2 carbon spacer arm. Maleimide modified oligo can be also incorporate post-synthetically which allow longer spacer in between functional group and oligonucleotide. 

We normally provides the oligonucleotide in lyophilized form in ready-to-use or protected state. Deprotection can be easily deprotected by Retro Diels-Alder reaction prior use. The Retro Diels-Alder reactions involves dehydration by co-evaporation with anhydrous acetonitrile and anhydrous toluene. The Retro Diels-Alder reaction requires anhydrous conditions and any significant level of moisture can cause incomplete deprotection, hydrolysis, and/or addition of water to the maleimide. The evaporation of the toluene leaves a white residue ready for conjugation. A detailed procedure is shipped with the product. An abbreviated procedure is described below.

  1. Suspend lyophilized oligo in 1 mL anhydrous Acetonitrile. It will be a suspension as oligo will NOT dissolve.
  2. Evaporate using a speedvac.
  3. Resuspend oligo in 1.5 mL Toulene.
  4. Incubate for 4 hrs at 90oC.
  5. Cool to room temperature.
  6. Evaporate toluene using a speedvac.
  7. The oligonucleotide is now ready for conjugation.

Contact Bio-Synthesis for Maleimide Oligonucleotide Synthesis and Modification Services.

Product Information


Product Name:



linker, cross linker

Modification Code:


Chemical Formula:


Exact Mass:


Formula Weight:



330.10 (100.0%), 331.10 (15.2%), 332.10 (2.3%)

Elemental Analysis:

C, 47.28; H, 5.80; N, 8.48; O, 29.06; P, 9.38


Bio-Synthesis Inc. Oligo Structure



Delivery Format:


Shipping Conditions:

Room Temperature

Storage Conditions:

-20°C To -70°C
Oligonucleotides are stable in solution at 4°C for up to 2 weeks. Properly reconstituted material stored at -20°C should be stable for at least 6 months. Dried DNA (when kept at -20°C) in a nuclease-free environment should be stable for years.