Bst 3.0 DNA Polymerase as Reverse Transcriptase?

Summary: Bst 3.0 is 3-24x higher yielding than homemade MMLV

Bst DNA pol is reported not only to have RT activity, but also to outperform most common RT enzymes. My own experiments validate this finding.

A paper from 2023 compared 5 RT enzymes (ImProm-II, Marathon RT, TGIRT-III, SuperScript IV, and BST 3.0 DNA polymerase) and found that Bst was about equal to the others in processivity and superior in yield.

Transcript	cDNA yield by qPCR (Bst relative to MMLV)
Structured	24
Unstructured low conc	3.0
Unstructured med conc	3.3
Unstructured high conc	5.1

Notes

• I tested a 100nt region of a mRNA in E coli total RNA
• I compared NEB Bst 3.0 vs homemade MMLV RT
• Further qPCR tests show that differences in the MMLV and Bst yield were not due to buffer effects on the qPCR rxns
• qPCR controls (no RT, calibration curve, no template) all looked good
• Bst 3.0 is way cheaper than SS IV (commercial MMLV). $0.66 vs $10 per 20uL rxn.

Reagent	Stock	Final	Volume(uL)
Isothermal buffer II	10x	1x	1.0
MgSO4	100mM	6mM	0.60
dNTP	10mM each	1.6mM each	1.6
RT primer	2uM	100nM	0.50
RNA		100ng/uL	varies
Bst 3.0 DNA Pol	8U/uL	0.64U/uL	0.80
Water			to 10uL