I am checking enzyme activity of asparginase (extracted from thermophilic bacteria) using nessler's reagent. But upon adding nessler's reagent white precipitates are formed, and they are hindering with absorbance at 450nm. Is there any method through which the precipitates can't be formed?
Dear Sadikhusain Suthar
The Nessler method has several interferences. For example, samples with a high hardness concentration (>500 ppm of CaCO3) can form a white precipitate when the Nessler reagent is added. This is due to the presence of unsoluble magnesium or/and calcium species.
The suggestions below can help to mitigate this interference: - Dilute the sample to minimize hardness below 500 mg/L (CaCO3). - Confirm the use of the Mineral Stabilizer Solution during the test method. - If sample dilution is not possible, add 1-2 drops of Rochelle Salt (Potassium sodium tartrate) or EDTA solutions to the sample prior to testing. Rochelle Salt or EDTA will complex the magnesium in solution.
I hope this helps you.
Exequiel
upon adding nessler's reagent white turbidity is formed, due to decrease of solubility which create the problem of optical density measurement. You can try addition of DMF or Acetonitrile.
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