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Table 2 Data used to determine the detection and quantification limits of the rtqPCR method for the amplification of the wt soybean sequence

From: Real-time quantification of wild-type contaminants in glyphosate tolerant soybean

Dilution levela 1 2 3 4 5 6 7
Expected wt DNA content (%) 5.00 1.00 0.20 0.04 0.0080 0.0016 0.0008
Estimated wt genome copies (n.) 8,889 1778 356 71 14.2 2.8 0.6
Signal rateb 9/9 9/9 9/9 9/9 9/9 6/9 6/9
Mean Ct value of positivesc 26.18 28.78 31.44 33.77 35.72 35.55 35.59
Mean CV of Ct values (%)d 0.78 0.84 0.71 1.85 2.28 - -
Estimated wt DNA content (%)e 5.00 0.82 0.13 0.026 0.0067 0.0075 0.0074
Bias (%)f 0 -18 -35 -35 -16 371 819
  1. aSerial dilutions 1:5 of 5% wt soybean DNA in RR soybean DNA (weight/weight)
  2. bproportion of PCR replicates yielding a positive signal
  3. cmean of nine values
  4. dCV calculated among PCR replicates
  5. ebased on the calibration curve passing through the point corresponding to the 5% wt with the observed Ct (26.18) and theoretical slope of -3.32
  6. fdeviation (%) between estimated and expected wt DNA content