Bio-Synthesis offer protected form and deprotected form of maleimide modified oligo. The protected state of maleimide modified oligonucleotide is deprotected using a retro Diels-Alder reaction. This can be done with microwave irradiation or by heating in toluene. The second approach is described below. Retro Diels-Alder reactions should be conducted in anhydrous conditions as exposure to significant levels of moisture can cause incomplete deprotection, hydrolysis and/or addition of water to the maleimide.
Deprotection by Heating in Toluene
1. Suspend lyophilized oligo in anhydrous toluene 1 to 2 mL
2. Let sit for 4 hrs at 90°C.
3. Cool to room temperature.
4. Evaporate toluene.
5. the oligonucleotide is now ready for conjugation.