Electrophoresis is one of a number of techniques that can be used to separate proteins with differing compositions. The technique was first used in the early 1960's to assess genetic variability in natural populations, and since then the amount of data of this type has grown enormously.

Both the technique and interpretation of the results are relatively simple, with the underlying assumption being that polypeptide variants for a specific protein reflect genetic differences among individuals. However, like all other quantitative techniques, the next step in the analysis of the results is to compute some simple descriptive statistics. The following are some of those that you may encounter in the literature:

Expected Frequency of Heterozygotes at a Locus (H): Assuming random mating with respect to this gene, the expected frequency of heterozygous individuals in the population would be:

The Effective Number of Alleles (n_e): Treats low frequency alleles as if they were relatively insignificant. The value of this number ranges from 1.0 to the total number of alleles that have been discovered.

The Average Frequency of Heterozygotes Per Locus (H_L): Simply take the expected frequency of heterozygotes at each locus (H), add them, and divide by the number of loci sampled (L).

The Average Proportion of Heterozygous Loci per Individual (H_I): This is calculated by determining the actual proportion of heterozygous loci in each individual, and then dividing by the number of individuals sampled (I).

Polymorphism: A gene is said to be polymorphic if the frequency of rare alleles is greater than can be explained by recurring mutation. There are two different numerical definitions of polymorphism: (1) Strict: if the frequency of the most common allele is less than 0.95; (2) Liberal: if the frequency of the most common allele is 0.99.