NESSLER’S REAGENT (For Serum Urea Nitrogen)

Nessler’s Reagent is an analytical reagent used for the determination of urea as ammonia. It is especially helpful when estimating ammonia production resulting from enzymatic hydrolysis of urea by microorganisms.
Urea is hydrolysed by some bacteria that produce the enzyme urease, releasing ammonia. Alternatively, instead of a pH indicator, Nessler’s Reagent can be used to detect the resulting alkalinity, which can detect the presence of ammonia. The reagent is also able to detect the ammonia that is produced by the breakdown of L-arginine.
In microbiological testing, an organism can be grown in the presence of urea and the resulting ammonia production can then be assessed. The reaction provides useful information about the organism’s biochemical activity and can support identification when used alongside other tests.
The reagent has a colourless to light-yellow appearance and passes the specified test for ammonia detection. For quantitative estimation, reaction time should be carefully controlled because the interaction between ammonia and Nessler’s Reagent can influence the accuracy of results.
Interfering substances may also have an effect on the Nessler method. Chlorine, chloride , hardness causing compounds such as magnesium ions and ferrous ions can give false results. Proper sample preparation and established analytical methods should be followed.

Determines urea through its conversion to ammonia, supporting biochemical assessment of urease activity in microorganisms.