Method of measuring the urease activity amount

摘要

PURPOSE:To rapidly and accurately measure an amount of urease activity, by decomposing urea with an urease extracted from a sample for definite time, subjecting the resulting NH2 to secondary reaction under specific conditions and determining the consumption of a specific substance. CONSTITUTION:Distilled water is added to a finely ground soybean to extract urease. The extracted urease is added to an urea solution to carry out urease reaction for definite time (normally 5min) and then acetohydroxamic acid which is an urease inhibitor is added thereto to stop decomposition reaction by urease and the resultant NH3 is subjected to secondary reaction in the presence of a glutamic acid dehydrogenase using alpha-ketoglutaric acid and nicotic amide adenindinucleotide (beta-NADH) and after the NH3 is completely reacted, the reaction liquid is moved into a spectroscopic cell, where 366nm absorbance (A366) is measured and urease activation amount (IU) contained in the reaction liquid is obtained from the formula. Activation concentration (IU/ml) is obtained from the activation amount and finally expressed as activity (IU/g) contained in soybean wt. unit.