Evaluation. Evaluation is performed by comparing the protein patterns of the unknown sample with reference standards on the same gel. Detection of cows' milk in cheeses from ewes' milk, goats' milk and buffalos' milk and mixtures of ewes', goats' and buffalos' milk is done via the a3- and a2-caseins, whose isolelectric points range between pH 6,5 and pH 7,5 (Figures 4 a, b, Figure 5). The detection limit is less than 0,5 %.
