Capping Reagent A – Ultramild
Tetrahydrofuran : Pyridine : Phenoxyacetic Anhydride (85:10:5 v/v/v)

This reagent is a capping reagent A formulation for ultramild oligonucleotide synthesis, composed of tetrahydrofuran (THF), pyridine, and phenoxyacetic anhydride in a 85:10:5 volume ratio.

• Composition: THF : pyridine : phenoxyacetic anhydride (85:10:5, v/v/v)
• Application: Capping reagent A for ultramild DNA/RNA synthesis protocols
• Function: Acetylation of unreacted 5’-hydroxyl groups
• Compatibility: Ideal for oligonucleotides with labile modifications
• Format: Ready-to-use

This gentler alternative to traditional acetic anhydride–based formulations helps preserve sensitive base modifications or terminal labels. Suitable for both manual and automated synthesizers.