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Old 10-12-2015, 08:24 AM   #165
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Originally Posted by Simone78 View Post
thatīs true, thanks for the explanation. I should have said "repackaged Superscript...with a twist" (changed few details to justify the new packaging)
Well, SuperScript II is wild-type MMLV RTase plus point mutations to kill the RNase H domain. In principle different companies could actually be selling different enzymes with different point mutations...

Originally Posted by Simone78 View Post
However, nowadays most or all of the RT protocols around are done with some kind of MMLV-based enzyme and wonīt differ so much from each other. My opinion, at least.
Even the fancier enzymes like SuperScript III and Maxima are, as far as I can tell, just engineered to be heat-resistant. That's what makes them more processive: you could run SuperScript II at 50 °C and it would probably be just as fast, except the enzyme would degrade too quickly to be very useful. Unfortunately this engineering tends to kill the C-tailing activity for some reason. But if you aren't using template-switching, mere heat resistance is still a legitimate improvement. (For sequencing I might still worry about increased error rates at the higher temperatures.)
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