Nitrate serves as a source of nitrogen for many bacteria and fungi, but in order to be utilized it must be broken down.Ready to use: Convenience of a prepared reagent.Ease of Differentiation: Positive test indicates red color development after addition of reagents; and no color development after addition of zinc dust. Negative test indicates no color development after addition of reagents and red color development after addition of zinc dust.Rapid Detection: Immediate results.The nitrite reduction test is a two-step procedure. Sulphanilic acid is added to acidify the medium and then naphthylamine is added which reacts with the nitrites to produce a red color. Certain bacteria convert nitrate to nitrite, ammonia, or gas. This process is denitrification. If no color develops after addition of reagents, the organism has either reduced the nitrate to free nitrogen or it has not attacked the nitrate at all. Nitrate will react with zinc dust to form nitrite. A pink to red color development after addition of zinc dust indicates that the nitrates are present, indicating a negative nitrite reduction test. No formation of a red color after addition of zinc dust indicates that the organism has reduced the nitrate to free nitrogen or ammonia and is considered a positive nitrate test2.Used in conjunction with Nitrate Reagent A, Part No. R21536.Not all products are available for sale in all territories. Please inquire.Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.