seconds every minute after decantation of the antimicrobial solution the swatches were washed with two 100 ml portions of 2 m sodium chloride solution for a 5 minute period with agitation followed by an overnight wash in running sterile water antimicrobial fabrics were subjected to two tests the relative ability of the treated fabric to kill bacteria is called the fabric efficacy level fel which is determined as follows a 4 34 u00d7 4 34 square of cloth was folded twice and then a measured volume of bacteria containing fluid was added to and adsorbed by the cloth the cloth was then incubated in a humid petri dish for a given period of time usually 30 minutes after which the cloth was placed in a medium that possessed a ph of 9 0 and shaken vigorously by a mechanical shaker to release the bacteria a measured quantity of fluid containing the released bacteria was added to an agar medium on a petri dish and the bacterial colonies were counted using an artek automatic counter the detection of diffusion of antimicrobials is by a leaching test in this test a sterile swab was dipped into a bacterial suspension and then used to.