A thin gel layer technique for improved resolution in two-dimensional immunoelectrophoresis.

A modification of the two-dimensional (crossed) immunoelectrophoresis (2D-IE) method characterized by the employment of a thin gel layer (0.3 mm) was developed. A rectangular Millipore filter dehydrates an area of the gel, thereby forming a basin which is charged with antiserum by means of a special applicator. This 2D-IE technique was compared with the techniques by Weeke [Scand. J. Immunol. 2: suppl. 1, pp. 47-56, 1973] and by Lebecq et al. [J. immunol. Methods 66: 219-226, 1984] using a model system comprising an antigen preparation from Mycobacterium intracellulare and a corresponding antiserum. Analyses by the technique described resulted in a distinct, multilinear precipitation pattern with dense and sharp precipitates contrasting well against the background.