Division 7.2 Densitometric estimationF1
If available, apply densitometry (5.19) for the determination of the peak area ratio of bovine to ovine, caprine and/or buffalo γ 2 - and γ 3 -caseins (see Figure 5). Compare this value to γ 2 - and γ 3 -casein peak area ratio of the 1 % reference standard (ewe, goat) or laboratory interim-standard (buffalo) analysed on the same gel.
A sample is judged as being positive, if both bovine γ 2 - and γ 3 -caseins or the corresponding peak area ratios are equal to or greater than the level of the 1 % reference standard.