The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
Use a concentration of 0.625 µg/ml.
Nalidixic acid (C12H12N2O3, systematic name 1-ethyl-7-methyl-4-oxo-[1,8]naphthyridine-3-carboxylic acid) is a quinolone antibiotic which inhibits DNA-gyrase. It is used in the treatment of urinary tract infections as it reaches high levels in the urine and is effective over the entire urinary pH range.
has not yet been referenced specifically in any publications.