myTXTL supports all promoters used in E. coli protein expression, including promoters that rely on the endogenous E. coli transcription machinery and those that require a separate RNA polymerase such as T7. Inducible plasmids require that the inducer be added to obtain the highest protein yield. pET (T7lac promoter) systems need 1 mM IPTG, for example, otherwise follow the guidance in the following table for inducer and plasmid concentrations in the myTXTL reaction.

We recommend the following inducer and plasmid concentrations when using some common inducible promoters:

PromoterInducerRecommended Inducer Concentration in myTXTLUnitsRecommended Plasmid Template Concentration in myTXTLUnits
T7lacIPTG1mM10nM
TetAaTc20µg/mL20nM
araBADL-Arabinose2%20nM
Return to FAQs main page