FAQ: Can Vaccinia Capping Enzyme (NEB #M2080) use cap analogs in capping reaction?

No. Vaccinia Capping Enzyme uses GTP and SAM to generate a cap structure on 5′ triphosphate RNA, typically a synthetic transcript generated by in vitro transcription. On the other hand, cap analogs, such as GpppG (NEB #S1407), m7GpppG (NEB #S1404), m7GpppA (NEB #S1405S) and anti-reverse cap analog (ARCA; NEB #S1411) are used during in vitro transcription, where the cap analog is directly incorporated into the transcript as the first nucleotide at the 5′ end.