The means of the absorbance values obtained for the standards and the samples were divided by the absorbance value of the first standard (zero standard) and multiplied by 100. The zero standard is thus equal to 100% and the absorbance values are quoted in percentages. The absorption is inversely proportional to the AFM1 concentration in the sample. The dilution factor was 1. In case of AFM1 concentrations higher that 80 ng/ml, samples were diluted with sample dilution buffer from the test kit and reanalyzed.