An excellent broad spectrum vial for the detection of anaerobic bacteria. It will accurately measure sulfate reducers as well, but is not specific to this type of bacteria. Operators experiencing difficulties associated with the testing of "sour" water may use this formula to obtain a 'worst-case' number for sulfate reducer. A slight, uniform turbidity is present in the sterile, unused vial, but the turbidity of a positive test is very obvious when compared with an unused vial. Since no iron is added, the media will not blacken in the presence of H2S. Normal salinity is 2,500 ppm as NaCl, but this can be varied to match the sample. Shelf life is 6 months if refrigerated and bottles come 288 per case standard.