Does the TaqMan Cells-to-CT Express Kit contain reagents for the removal of genomic DNA (gDNA)?
Yes, the TaqMan Cells-to-CT Express Kit includes Express ezDNase which can be added to the Express Lysis Solution for removal of gDNA during cell lysis. Express ezDNase is a double-strand specific, heat-labile DNase that will only digest gDNA, making it compatible with the downstream reverse transcription reaction. The enzyme is automatically inactivated during a heat kill step included in the reverse transcription program. To avoid the detection of gDNA, we recommend using a TaqMan Gene Expression Assay specifically designed to span an intron-exon boundary. Such assays are designated with an "_m1" suffix. More information can be found here.
Find additional tips, troubleshooting help, and resources within our Real-Time PCR and Digital PCR Applications Support Center.
In your SuperScript IV RT protocols, there is no ezDNase inactivation step. Will active ezDNase affect RNA or the RT reaction?
The Invitrogen ezDNase Enzyme is a novel DNase that is highly specific for double-stranded DNA. It has no activity on single-stranded DNA in RT reactions (primers or probes), or on RNA. The enzyme is also thermolabile—it is inactivated quickly at temperatures typical for the SuperScript IV RT reaction (e.g., 50°C). The additional inactivation step is therefore not required in RT-qPCR applications.
Find additional tips, troubleshooting help, and resources within our PCR and cDNA Synthesis Support Center.
Which SuperScript IV RT format do you recommend for real-time PCR applications?
For RT-qPCR applications we recommend using the Invitrogen SuperScript IV VILO Master Mix (Cat. No. 11756050). The cDNA synthesis reaction setup with this master mix requires fewer pipetting steps and therefore reduces variation in the data. SuperScript IV RT, as a component of the master mix, offers the highest efficiency of cDNA synthesis step compared to competitors’ products.
Find additional tips, troubleshooting help, and resources within our PCR and cDNA Synthesis Support Center.
Are there any significant changes in the SuperScript IV RT protocol compared to the SuperScript III RT protocol?
The only change is that the incubation time for the reverse transcription reaction has been reduced from 50 minutes to 10 minutes. All the other parameters and steps are the same.
Find additional tips, troubleshooting help, and resources within our PCR and cDNA Synthesis Support Center.