Crop Biotech Update

Determination of Cry1Ab in Soils Used for Bt Maize Field Trials

April 29, 2011

Bt maize (MON810) produce Cry1Ab, an insecticidal protein, which protects the crop from infestation of target organisms. Scientist Helga Gruber at the Institute for Crop Science and Plant Breeding, Germany, together with other researchers, investigated the fate of Cry1Ab in soil samples from plots used for experimental field trials of Bt maize for nine growing seasons. Cry1Ab protein in soil (less than 2 mm in size) using an in-house enzyme immunoassay was validated using the criteria in European Commission Decision 2002/657/EC.

The protein was only detected in one out of the four sites. The protein concentration is higher than the decision limit of 2.0 ng Cry1Ab protein g-1 soil in top and lower soil samples, which were collected six weeks after the growing season. However, there were no traces of Cry1Ab in all field sites during time for next planting season. Thus, no evidence for long-term accumulation of Cry1Ab can be drawn from this study.

The abstract is available at