Transgenic Research

, Volume 16, Issue 1, pp 51–63 | Cite as

Sources of uncertainty in the quantification of genetically modified oilseed rape contamination in seed lots

  • Graham S. Begg
  • Danny W. Cullen
  • Pietro P. M. Iannetta
  • Geoff R. Squire
Original Paper


Testing of seed and grain lots is essential in the enforcement of GM labelling legislation and needs reliable procedures for which associated errors have been identified and minimised. In this paper we consider the testing of oilseed rape seed lots obtained from the harvest of a non-GM crop known to be contaminated by volunteer plants from a GM herbicide tolerant variety. The objective was to identify and quantify the error associated with the testing of these lots from the initial sampling to completion of the real-time PCR assay with which the level of GM contamination was quantified.

The results showed that, under the controlled conditions of a single laboratory, the error associated with the real-time PCR assay to be negligible in comparison with sampling error, which was exacerbated by heterogeneity in the distribution of GM seeds, most notably at a small scale, i.e. 25 cm3. Sampling error was reduced by one to two thirds on the application of appropriate homogenisation procedures.


Genetic modification Seed lot Sampling error Measurement error Heterogeneity Real-time PCR 



We wish to thank Geoff Robertson, Martin Elliott, Gill Banks and Joyce McKlusky for their technical assistance. This study was supported by the Scottish Executive Environment and Rural Affairs Department and Department of Environment, Food and Rural Affairs (Defra)


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Copyright information

© Springer Science+Business Media B.V. 2006

Authors and Affiliations

  • Graham S. Begg
    • 1
  • Danny W. Cullen
    • 1
  • Pietro P. M. Iannetta
    • 1
  • Geoff R. Squire
    • 1
  1. 1.Scottish Crop Research InstituteDundeeUK

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