TaqMan™ GTXpress™ 预混液

We recommend using either the TaqPath ProAmp Master Mix or the TaqMan Genotyping Master Mix. The TaqMan Genotyping Master Mix has the advantage of proven performance with up to 3 days of pre- and post-PCR stability, allowing you to set up plates ahead of time or read the plates later (see the data here, https://tools.thermofisher.com/content/sfs/brochures/cms_039236.pdf) while the TaqPath ProAmp Master Mix can handle samples that may have inhibitors present.

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)

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).

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).

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.