Rapid characterisation of (glyphosate tolerant) transgenic and non-transgenic soybeans using chromatographic protein profiles

The characterisation of transgenic and non-transgenic soybeans was performed in this work based on the examination of their protein profiles obtained by rapid chromatographic techniques. Two reversed-phase chromatographic methods using monolithic and perfusion stationary phases were applied to the separation of soybean proteins from different transgenic and non-transgenic soybeans. The development of the monolithic LC methodology was carried out through the study of the influence of different parameters such as gradient, ion-pairing reagent, and temperature on the separation of soybean proteins. Results from monolithic LC analysis were compared with those obtained by perfusion LC using a method previously developed by our research team. Perfusion and monolithic LC enabled the separation of soybean proteins in less than 3 and 8 min, respectively. In both cases, there were certain features in the chromatograms that seemed to be characteristic of transgenic samples. A deeper analysis of chromatographic profiles was then performed by the application of multivariate classification techniques. Results from these multivariate techniques showed that the two methods presented similar classification capabilities being both suitable for the characterisation of transgenic and non-transgenic soybeans. A more robust mathematical model was built with the data obtained by the perfusion method using 10 additional samples for training (a total of 26 samples), obtaining a 96.2% of correct classification. This model was validated by a cross-validation procedure (80.8% of correct classification) and by the correct classification of 15 out of 16 blind samples.