An electrophoresis gel showing DNA profiles from six different cows with lanes 1 and 2 being the optimal breeding pair. To be selected for the premium market, the calves must come from this optimal pair. If they do, they would match with a band from both the mother and the father in each STR area.

The rows marked L have DNA fragments of known lengths, which act as a scale to compare the lengths of the bands in the other samples.