Wheat gliadin: Digital imaging and database construction using a 4‐band reference system of agarose isoelectric focusing patterns

An isoelectric focusing method using thin‐layer agarose gel has been developed for wheat gliadin. Using flat‐bed units with a third electrode, up to 72 samples per gel may be analyzed. Advantages over traditional acid polyacrylamide gel electrophoresis methodology include: faster run times, nontoxic media, and greater sample capacity. The method is suitable for fingerprinting or purity testing of wheat varieties. Using digital images captured by a flat‐bed scanner, a 4‐band reference system using isoelectric points was devised. Software enables separated bands to be assigned p I values based upon reference tracks. Precision of assigned isoelectric points is shown to be on the order of 0.02 pH units. Captured images may be stored in a computer database and compared to unknown patterns to enable an identification. Parameters for a match with a stored pattern may be adjusted for p I interval required for a match, and number of best matches.