Agarose gels can be run at various voltages, depending on the separation desired and the available time. As depicted also in Fig. 7, agarose gels can be used to separate PCR products of plymorphic loci. In most cases, two or three bands appear, due to heteroduplex formation between the long and short alleles. In mixture K, products were chosen so they differ by no less than 5 bp and no more than 45 bp. As depicted in Fig. 7 and Fig.
Bands become to overlap and it is difficult or impossible to find and label each band.
Multiplex PCR amplification of mixture K, using four different DNA samples. As depicted also in Fig. 7, 2-3 bands become visible for each product. It is unclear where the extra band originates when only one allele is amplified. Denaturing PAA gels, however, are more expensive, time consuming and might prove technically more difficult. Primers amplify nonpolymorphic loci.