Binding of CelB derivatives to Avicel as assessed by SDS-PAGE. The sizes (in kilodaltons) of molecular mass standards are indicated to the left of each gel. Lanes: M1, molecular mass marker; 1, untreated r 4, untreated rIg-PfamB; 5; unbound rIg-PfamB; 6, bound rIg-PfamB; 7, untreated rIg; 8, unbound rIg; 9, bound rIg; 10, untreated rIg-PfamB; 11, unbound rIg-PfamB; 12, bound rIg-PfamB.