Fig. 2. SDS-polyacrylamide gradient gel electrophoresis (SDS PAGGE) (5–25% acrylamide gradient slab gel) under reducing conditions. (A) Gel stained with Coomassie Brilliant Blue R250 (lanes 1 and 2) and (B) immunodetection of proteins blotted on Immobilon-P (Millipore) membrane using mAb anti-MPII of gut supernatants from control and acute Cd-exposed worms (20 mg l^–1, 2 days). Lane 3, molecular mass markers (kDa): 14.4, -lactalbumin; 20, trypsin inhibitor; 30, carbonic anhydrase; 43, ovalbumin; 67, albumin; 94, phosphorylase. Immunodetection of proteins from chromatographic fractions (see text) of gut supernatants revealed a main band of molecular mass <14.4 kDa and of similar intensity in control (lane 4) and Cd-exposed worms (lane 5).