Glen Report 32-23: New Products - ÄKTA Capping Reagents

The ÄKTA OligoPilot Plus (10/100) oligonucleotide synthesizers are popular for small to medium scale operations. The instruments are supported by UNICORN control software, and its HPLC-driven system makes it flexible and reagent-efficient. Many of our customers use ÄKTA OligoPilot systems, and we have a set of standard ÄKTA-compatible reagents that can be found at the following link:

For capping, Glen Research has historically offered the following:

Cap A 20 % Methylimidazole in Acetonitrile (40-4015)
Cap B 20 % Acetic Anhydride and 30 % 2,6-Lutidine in Acetonitrile (40-4028)

The Cap B mixture is actually an equal mix of two solutions: 40 % acetic anhydride/acetonitrile and 60 % 2,6-lutidine/acetonitrile. Ideally, these two would be mixed by the end user prior to loading onto the instrument, but regulatory restrictions make such an option challenging. Instead, the mixing is performed at Glen Research just prior to shipping. The resulting mixture has a relatively short half-life and we recommend that the solution is used within 8 weeks of the mixing date.

To address this short shelf life, Glen Research is introducing a new set of capping reagents for the ÄKTA instrument line:

Cap A 30 % 2,6-Luditine/20 % Methylimidazole/Acetonitrile
Cap B 20 % Acetic Anhydride in Acetonitrile
Cap B 5 % Phenoxyacetic Anhydride in Acetonitrile

These Cap B formulations are much more stable than our traditional offerings, with a reanalysis date of one year following release. In addition to standard capping, we are also making an UltraMild Cap B available for syntheses that require UltraMild conditions. We hope that users of ÄKTA instruments find these new formulations useful in the capping step of the oligonucleotide synthesis cycle.

Product Information

Cap Mix A Acetonitrile/Methylimidazole (40-4015-71)

Cap Mix B Acetonitrile/Acetic Anhydride/2,6-Lutidine (40-4028-71)

Cap Mix A 20% 1-Methylimidazole in Acetonitrile/ 2,6-Lutidine (40-4115-71)

Cap Mix B 20% Acetic Anhydride in Acetonitrile (40-4224-71) - Contact customer service for availability

Cap Mix B 5% Phenoxyacetic Anhydride in Acetonitrile (40-4128-71)