Tarkeshwar, two quick questions come to my mind readily: (1) what sort of in vitro transcription kit do are you looking to improvise? Those based on bacterial/viral polymerases like SP6/T3/T7 or using eukaryotic PolII? (2) Which kit do you have in mind to improvise? Unless we know which base-state you are going to improvise and unless we understand that base-state well, it is difficult to think about any improvisation.

Dear Tarkeshwar. We are using quite often both the MegaScript and mMessage Machine kits from Ambion/Life Technologies (both T7 and SP6 versions) and in general we are happy with the yields. Why do you think they need to be improved?