The researchers analyzed the glutenin proteins in wheat hybrid progenies using a gel electrophoresis method. They found different types of high-molecular-weight subunits in the glutenin at specific genetic loci. The most common subunits were 1 and N in Glu-A1, 13+16 in Glu-B1, and 5+10 in Glu-D1, which is considered the highest quality subunit pair. The frequency of these subunit combinations varied, with subunit 1 being the most common in Glu-A1, and subunit pair 5+10 being the most common in Glu-D1.