A chopped glass fiber conjugate pad cut to 29 mm width (Ahlstrom-Munksjö, Helsinki, Finland, product 8951) and blocked with a solution of 0.05%, 1-day aged casein, 5 mM borate, and 0.2% w/v sucrose. The entire conjugate pad was submerged in the blocking solution for 15 minutes with continuous rocking. The nitrocellulose was removed and dried in a 25°C forced-air oven.