I am trying to do an in-vitro transcription of sars-cov-2 dna which is around 30 kb for this i am using mMachine mmessage T7 transcription kit omponent

For transcribing full-length RNA

2× NTP/CAP

25 μL

GTP

7.5 μL

10× reaction buffer

5 μL

DNA template

Up to 7.5 μL (use 1–2 μg)

Enzyme mix

5 μL

Nuclease-free water

Top up to 50 μL

after that i incubate the reaction at 32*C for 8 hrs so far the IVT has been unsuccessful any suggestion or input will be highly Thankful.

https://www.nature.com/articles/s41596-021-00491-8#Sec47 i am using this paper