Thermo Scientific™ Nitrate Broth with Durham Tube

Description

• Determine nitrate reduction by bacteria using Thermo Scientific™ Remel™ Nitrate Broth with Durham Tube
• The ability to reduce nitrate to nitrite can be used to differentiate and identify various bacteria and is characteristic of the family Enterobacteriaceae 1
• Nitrate serves as the source of nitrogen for many bacteria and fungi, but it must be broken down to be utilized
• In 1962, Daubner reported that all members of the Enterobacteriaceae tested, with the exception of Erwinia species, reduced nitrate in eight hours 2
• Organisms that possess nitrate reductase can reduce nitrate to nitrite
• Certain bacteria convert nitrate to nitrite, ammonia or nitrogen gas
• This process is referred to as denitrification
• Nonfermenters and other miscellaneous gram-negative bacilli vary in their ability to reduce nitrates, some being capable of further reducing nitrite to nitrogen gas
• The end product of reduction depends on the bacterial species 3
• Ready to use: Prepared liquid media
• Rapid test: Results within 5-10 minutes
• Easy to interpret: When zinc dust is added, a red color indicates the presence of unreacted nitrate
• Available in 2 formats : With Durham Tube (R061534 and R061536), without Durham Tube (R061530 and R061532)
• This medium contains 0.1% potassium nitrate (KNO 3 ) that acts as a substrate to determine nitrate breakdown
• Enterobacteriaceae spp
• typically reduce nitrate to nitrite
• The presence of nitrite is determined by the addition of sulfanilic acid which reacts with the nitrite to form a diazonium salt
• This salt then couples with N,N-Dimethyl-α-naphthylamine to form a red dye complex
• Certain organisms reduce nitrite to ammonia or nitrogen gas, leaving no nitrite to react with sulfanilic acid and yielding a colorless result
• An additional test must then be performed by adding zinc dust to test for the presence of unreacted nitrate
• Zinc dust catalyzes the reaction of nitrate to nitrite
• A positive test indicates development of red color within 1-2 minutes after addition of Nitrate Reagents A (R21239) and B (R21242) or no color change within 5-10 minutes after addition of zinc dust
• A negative test indicates no color development within 1-2 minutes after addition of Nitrate Reagents A and B and red color development within 5-10 minutes after addition of zinc dust
• Therefore, the nitrate reduction test is evidenced by either the presence of a catabolic end product or the absence of nitrate in the medium 3
• Not all products are available for sale in all territories
• Please inquire
• Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.