Micro-fluidic capillary electrophoresis methodology was developed to analyse grain DNA composition, thus to provide unequivocal distinction between varieties of wheat (Triticum aestivum L) and of barley (Hordeum vulgare L). This 'Lab-on-a-chip' technology complements protein composition analysis by micro-fluidic capillary electrophoresis, which is already in routine use for variety identification. Whereas it had been difficult to distinguish between some varieties by protein analysis using the Lab-on-a-chip system, distinctions proved to be possible using a combination of DNA extraction and microsatellite analysis, taking advantage of the speed and convenience of DNA chips. Several combinations of microsatellites permitted the DNA analysis system to provide distinction between two wheat varieties and between all but two (Chebec and Schooner) of the main eleven Australian barley varieties (Arapiles, Baudin, Barque, Chebec, Gairdner, Grimmett, Lindwall, Parwan, Schooner, Skiff and Sloop). Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.