Isoelectrofocusing in the study of the Bf system: existence of two common subtypes of the BfF allele

The inherited polymorphism of the properdin factor B (Bf system) was studied by isoelectrofocusing in polyacrylamide gel (PAGIF, pH range 5.0-8.0), followed by immunofixation. Using the described technique, two different subtypes of F bands are visible (designated as F' and F"). Studies of 13 families and 48 mother-child pairs are not in contradiction to the assumption of a codominant inheritance by two alleles (BfF' and BfF") at a single locus.