Pyrex Dish containing Gel Holder Cassette

The cassette is assembled by building a sandwich on top of the black plate. The sandwich is built by placing a fiber pad, 2-3 layers of filter paper, the gel, the membrane, 2-3 layers of filter paper, and a fiber pad on top of the black cassette. The red cassette then folds on top of the sandwich and is locked to keep the layers in place.