tokens: Samples ( 1 g ) were extracted with 0 . 5 % potassium chloride ( KCl ) in 70 % methanol ( 5 ml ) and diluted subsequently to give two - fold to ten - fold step - wise dilutions in phosphate - buffered saline containing 0 . 05 % Tween 20 and 0 . 2 % bovine serum albumin ( PBS - T BSA ) .