 Diluent is a nontoxic solution that is made up of 2% NaCl in Ultra Pure Water.This solution is used for diluting the sample and the reagent, and also provides osmotic protection that is required by "Allivibrio fischeri".Microtox can be applied to a variety of matrices including drinking water, stormwater runoff, effluent, industrial discharges, soils and sediments.