The membrane samples were cut into squares
of 25 25 mm2 (triplicate samples were used for statistical
purposes), immersed in 15 mL of PBS (pH 7.4; 0.8 g NaCl;
0.2 g KCl; 1.44 g Na2HPO4.2H2O and 0.2 g KH2PO4 dissolved
in 1 L of distilled water) and incubated in an air circulation
oven (HERAEUS Vacuotherm) at 37 C for 15 days.