Porter Fregments Void volume (ml) Proter Fragments Hinge region F(ab) Pepsin was also found to digest IgG into fragments (F(ab')2 and pFc fragments).By 1960 Gerald Edelman treated IgG with reducing agents,such as mercaptoethanol,in Pepsin was also found to digest IgG into fragments (F(ab')2 and pFc fragments). By 1960 Gerald Edelman treated IgG with reducing agents, such as mercaptoethanol, in