Effect of oil extraction and temperature on maize-produced HBsAg, as determined by immunoblot. Arrowhead indicates monomeric form of HBsAg. L, prestained protein ladder; Std, 100ng yeast-derived rHBsAg standard; Neg ctrl, non-transgenic maize material; FF, full fat HBsAg maize; SFE, supercritical fluid extracted maize; Hex, hexane extracted maize. All maize samples were loaded at 1.5μg of total protein with the exception of the full fat sample treated at 80°C which was loaded at a maximum well volume (equivalent to 0.5μg). This corresponds to 0.2 to 0.3mg of starting maize material in lanes 3 through 9 and 0.5mg in lane 10.