Analytical and Bioanalytical Chemistry

, Volume 396, Issue 6, pp 2103–2112

Validation of a newly developed hexaplex real-time PCR assay for screening for presence of GMOs in food, feed and seed

Original Paper

DOI: 10.1007/s00216-009-3380-x

Cite this article as:
Bahrdt, C., Krech, A.B., Wurz, A. et al. Anal Bioanal Chem (2010) 396: 2103. doi:10.1007/s00216-009-3380-x


For years, an increasing number and diversity of genetically modified plants has been grown on a commercial scale. The need for detection and identification of these genetically modified organisms (GMOs) calls for broad and at the same time flexible high throughput testing methods. Here we describe the development and validation of a hexaplex real-time polymerase chain reaction (PCR) screening assay covering more than 100 approved GMOs containing at least one of the GMO targets of the assay. The assay comprises detection systems for Cauliflower Mosaic Virus 35S promoter, Agrobacterium tumefaciens NOS terminator, Figwort Mosaic Virus 34S promoter and two construct-specific sequences present in novel genetically modified soybean and maize that lack common screening elements. Additionally a detection system for an internal positive control (IPC) indicating the presence or absence of PCR inhibiting substances was included. The six real-time PCR systems were allocated to five detection channels showing no significant crosstalk between the detection channels. As part of an extensive validation, a limit of detection (LODabs) ≤ ten target copies was proven in hexaplex format. A sensitivity ≤ ten target copies of each GMO detection system was still shown in highly asymmetric target situations in the presence of 1,000 copies of all other GMO targets of each detection channel. Furthermore, the applicability to a broad sample spectrum and reliable indication of inhibition by the IPC system was demonstrated. The presented hexaplex assay offers sensitive and reliable detection of GMOs in processed and unprocessed food, feed and seed samples with high efficiency.

PCR amplification curves of all PCR systems comprised in the hexaplex real-time PCR assay for screening for presence of GMOs in food, feed and seed with 50 target copies per reaction.


GMOMultiplexHexaplexReal-time PCRScreeningValidation

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Eurofins GeneScan GmbHFreiburgGermany