Development of a dual-label time-resolved fluorometric immunoassay for the simultaneous detection of two recombinant proteins in potato.

Immunological methods such as ELISA have been traditionally employed to quantify protein levels in plants improved through modern biotechnology. Combined trait products (i.e., plants producing multiple recombinant proteins) created by introducing multiple genetic traits by transformation or traditional breeding methods have prompted the need for the development of analytical assay technologies capable of detecting and quantifying multiple proteins in a single assay. The development of a two-site, sandwich, dual-label, time-resolved fluorometry-based immunoassay (TRFIA) capable of simultaneously quantitating two recombinant proteins (CP4 EPSPS and Cry3A) in plant sample extracts of genetically improved potato cultivars is reported here. The performance characteristics of TRFIA were similar to or exceeded those of current ELISA methods used to detect and quantitate these proteins. TRFIA is a practical and reliable assay for the quantitation of proteins in genetically improved potato plants and offers an alternative approach to conventional ELISA methods with the added benefit of multiple analyte detection.

Compositional analysis of tubers from insect and virus resistant potato plants.

Genetically modified potato plants that are resistant to the Colorado potato beetle, plus either the potato leaf roll virus or potato virus Y, have recently been commercialized. As part of the safety assessment for plants produced by modern biotechnology, the composition of the food/feed must be compared to that of the food/feed produced by an equivalent plant variety from a conventional source. The composition of important nutritional and antinutritional factors in tubers produced by virus- and insect-resistant potato plants were compared to tubers produced by conventional potato plants. Key nutritional, quality, and antinutritional components measured were total solids, vitamin C, dextrose, sucrose, soluble protein, and glycoalkaloids. Proximate analyses included fat, ash, calories, total protein, and crude fiber. Minor nutrients measured were vitamin B6, niacin, copper, magnesium, potassium, and amino acids. The results from these analyses confirm that tubers produced by insect- and virus-protected varieties are substantially equivalent to tubers produced by conventional potato varieties.