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The Use of 35S and Tnos Expression Elements in the Measurement of Genetically Engineered Plant Materials



Marcia J. Holden, Marci Levine, Tandace Scholdberg, Ross J. Haynes, G. Ronald Jenkins


An online survey was conducted by the International Life Sciences Institute International, Food Biotechnology Committee, on the use of qualitative and quantitative Polymerase Chain Reaction (PCR) assays for Cauliflower Mosaic Virus 35S promoter and Agrobacterium tumefaciens Tnos DNA sequence elements for the detection of genetically engineered crop plant material. Forty-four testing laboratories around the world completed the survey. The results showed that the wide-spread use of such methods, the multiplicity of published and in-house methods and the variety of reference materials and calibrants also in use. There was an interest on the part of respondents in validated quantitative assays relevant to all GE events that contain these elements. Data is presented using two variations of five published 35S assays on eight maize reference materials. The results showed that two of the five methods were not suitable for all the eight reference materials, showing poor linear regression parameters and multiple products with some of the reference materials. This preliminary study demonstrates that all 35S methods are not the same and the need for validation.
Analytical and Bioanalytical Chemistry


Cauliflower mosaic virus, CaMV, 35S promoter, Tnos, genetically engineered, qualitative polymerase chain reaction, PCR, quantitative real-time PCR


Holden, M. , Levine, M. , Scholdberg, T. , Haynes, R. and , G. (2010), The Use of 35S and Tnos Expression Elements in the Measurement of Genetically Engineered Plant Materials, Analytical and Bioanalytical Chemistry, [online], (Accessed April 21, 2024)
Created March 1, 2010, Updated February 19, 2017