Enzymic creatinine assay: a new colorimetric method based on hydrogen peroxide measurement.

Abstract

We describe a new colorimetric method for measuring creatinine in serum and urine. Creatinine hydrolysis is catalyzed by creatinine amidohydrolase, and the creatine so produced is assayed in reactions catalyzed sequentially by creatine amidinohydrolase and sarcosine oxidase in a system that generates hydrogen peroxide. The hydrogen peroxide is measured at 510 nm in a reaction catalyzed by horseradish peroxidase, with 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone as the chromogen. This series of reactions is complete in 30 min at room temperature. A blank sample measurement corrects for endogenous creatine. The standard curve is linear for creatinine concentrations as great as 2.21 mmol/L. Analytical recovery of creatinine in human sera and urine averaged 99.8%. Within-run and between-run precision studies gave CVs of less than or equal to 3.3 and less than or equal to 4.3% for a serum with a creatinine concentration of 69 mumol/L. Results by this method agree well (r greater than 0.99) with those by both the enzymic ultraviolet method of Wahlefeld and the fuller's earth/Jaffé method.

Evaluation of physiological measures for correcting variation in urinary output: Implications for assessing environmental chemical exposure in children

“…Another advantage of measuring specific gravity over creatinine is the simplicity of the analytical method. Creatinine is commonly determined using several different colormetric assays (Fossati et al, 1983;Distasio et al, 1988;Larpent and Verger, 1990;Mei and Wu, 2002;Olsson et al, 2004;Dai, 2007;Keppler et al, 2007), whereas specific gravity can be measured using a handheld refractometer that is easy and inexpensive to use and generates no chemical waste. The primary drawback of measuring specific gravity is that the measurement should be taken when the urine sample is still fresh, not after the sample has been frozen.…”

Pharmacological studies on the efficacy of a thymoquinone‐containing novel polyherbal formulation against cisplatin‐induced hepatorenal toxicity in rats

“…The serum obtained was used to assess liver function parameters like Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), cholesterol, and kidney function parameters such as Blood urea nitrogen (BUN), serum urea concentration, total protein, and serum creatinine. The estimation of ALT was carried out as described by Reitman and Frankel (1957), AST, as per the method of Thomas (1998), total protein by the Biuret method modified by Iroanya, Adebesin, and Okpuzor (2014), and serum urea and creatinine, according to Orsonneau, Massoubre, Cabanes, and Lustenberger (1992) and Fossati, Prencipe, and Berti (1983), respectively.…”

Ginseng Ameliorates Effect of Prolonged Use of Omeprazole in Rat Renal Cortex through Decreasing Inflammation, Fibrosis and Apoptosis

“…The blood samples were allowed to stand for about 30 minutes to clot and centrifuged for 15 min. Sera were separated and used to determine the levels using ready to use creatinine (Fossati et al, 1983) and urea kits (Tietz, 1995) .…”