The diffusion method is based on monitoring the
growth inhibition of a specific microorganism caused by
a certain concentration of the tested specimen.
The results
of the tests are shown as inhibition zones (I) expressed
in mm.
When using the diffusion method, the test samples
were dissolved in dimethyl sulfoxide (99.5 % DMSO) to
obtain a 1 mg/mL stock solution
The inhibition zones
for bacteria were measured in millimeters at the end of
an 18-hour incubation period at 37 °C.