Multiplexed Quantification of Transgenic Proteins in Genetically Modified Maize Using Electrochemiluminescence Technology.

The current method for quantitative analysis of transgenic protein expression in genetically modified maize is limited to single-plex assays, small dynamic ranges, and several throughput-limiting steps. The transgenic protein products of interest confer insect or herbicide resistance and can be combined to make complex stacked trait packages. Due to increases in sample volume and complexity in the analysis of stacked traits, a quantitative multiplex assay for specific transgenic proteins has been developed. Using Meso Scale Discovery’s (MSD) electrochemiluminescense (ECL) technology, a high-throughput quantitative multiplex assay to detect proprietary transgene expression products in maize has been developed. Protein specific antibodies were screened using anti-species detection methods to identify optimal pairing combinations, and then were coupled with the MSD SULFO-TAG™ molecule. Fresh maize leaf tissue was homogenized and the supernatant extracted. A small dilution was performed before assaying each sample in concordance with protein standards. Step-wise and co-incubation assays have been tested and show good results with insignificant non-specific binding. Raw detection data was collected using the MSD Sector Imager 6000 and ECL signals were interpolated into a standard curve to produce a final expression result for each protein. Several protein combinations were evaluated and one was selected for implementation.