A continuous acetic acid system for polyacrylamide gel electrophoresis (1)
Gelscontaining 12% total acrylamide with 3% cross-linkage (12%T , 3%C) was prepared according to the three formulations.
It was shown that Patterns resulting from electrophoresis of ten cultivars using (a) a conventional aluminum lactate system, (b) the discontinuous aluminum lactate-lactic acid system, and (c) the continuous acetic acid system. The lactate systems (a and b) gave essentially identical patterns. However, the continuous acetic acid system produced patterns that showed distinct variations from patterns from the lactate-buffered gels.
Type I, Adena and Blueboy (a single heavy band); Type II, Abe and Arthur (two closely spaced heavy bands); Type III, Compton, Hillsdale and Geneva (two widely spaced heavy bands); Type IV, Caldwell, Houser, and Hart. The cultivar Compton appears to be unique in that the two bands underconsideration are of intermediate spacing, i. e., more widely spaced than the two bands of Type II but more closely spaced than the two bands of other Type III varieties.
Application of the acetic acid system to cultivars grouped according to type shows that typical cultivars of Type I, II, and III all respond in the same way, with an additional band appearing among the bands that fall in the area considered for classification. Type IV is quite heterogeneous, and inspection of Type IV patterns suggests that this group can be divided into subgroups.
In general, patterns obtained from the acetic acid system exhibit more bands than do patterns from lactate systems. The system has also given excellent patterns with extracts of cereals other than wheats.
The acetic acid gels (pH 2.7) are more acidic than the lactate gels (pH 3.1-3.2), and the lower pH may account for resolution into additional bands. Conformation of gliadin molecules is different in acetic acid than in aluminum lactate. Acetic acid reacts with hydrogen peroxide to give peracetic acid and that the latter is incompatible with methacrylate plastics. As a rule, the acetic acid gels require reduced loads as compared with loads required for lactate gels.