With the AgPath-ID One-Step RT-PCR Reagents, I am getting signal detection in the no-template control (NTC) reaction. Why is this?
This is likely due to PCR contamination. Here are some recommendations:
- Repeat the qRT-PCR reaction with fresh reagents and decontaminated pipettors.
- Set up and run the qRT-PCR reaction in an area that is isolated from areas used for nucleic acid isolation and PCR product analysis.
- The Reverse Transcriptase enzyme contained in this kit is produced using an E. coli expression vector containing a proprietary version of the MMLV pol gene (GenBank accession no. J02255) expressed from pET-24(+). It is possible that a minimal amount of the expression vector could be carried over into the final mastermix formulation. If you are targeting MMLV, a related virus, or any of the plasmid sequence, we recommend designing primer sequences for target sequences not contained in the expression vector.
What can I do to improve the sensitivity of my qPCR assay?
If you are targeting a low-abundance gene, you may have trouble getting Ct values in a good, reliable range (Ct > 32). To increase the sensitivity of the assay, you may want to consider the following:
- Increase the amount of RNA input into your reverse transcription reaction, if possible
- Increase the amount of cDNA in your qPCR reaction (20% by volume max)
- Try a different reverse transcription kit, such as our SuperScript VILO Master Mix, for the highest cDNA yield possible
- Consider trying a one-step or Cells-to-CT type workflow (depending on your sample type)
How do I set the baseline for my qPCR experiment?
Most times your instrument software can automatically set a proper baseline for your data. Check out our short video, Understanding Baselines, for more information on how to set them (https://www.youtube.com/watch?feature=player_embedded&v=5BjFAJHW-bE).
How do I set the threshold for my qPCR experiment?
In most cases your instrument software can automatically set a proper threshold for your data. Check out our short video, Understanding Thresholds, for more information on how to set them (https://www.youtube.com/watch?feature=player_embedded&v=H_xsuRQIM9M).
I am not getting any amplification with my TaqMan Assay or SYBR Green primer set. What is causing this?
There could be several reasons for no amplification from an assay or primer set. Please see these examples and suggested solutions in our Real-Time Troubleshooting Tool (https://www.thermofisher.com/us/en/home/life-science/pcr/real-time-pcr/qpcr-education/real-time-pcr-troubleshooting-tool/gene-expression-quantitation-troubleshooting/no-amplification.html) for more details.