Clinical Chemistry, Vol 21, 1422-1426, Copyright © 1975 by the American Association for Clinical Chemistry

Kinetic Enzymatic Method for Determining Serum Creatinine

¹ Research and Development Division, Worthington Biochemical Corp., Freehold, N. J. 07728.

Creatinine amidohydrolase is used to measure serum creatinine in a totally enzymatic procedure. Creatine, produced by hydrolysis, is acted upon by creatine kinase, and then by pyruvate kinase and lactate dehydrogenase, to result in a change in absorbance at 340 nm. The amount of creatinine present is related to the rate of change in A₃₄₀ and is determined from a standard curve. Absorbance and concentration are linearly related to 100 mg/liter and only 250 µl of serum is required. At 1.0 g/liter, heparin, oxalate, citrate, ethylenediaminetetraacetate, ascorbate, or glucose had no significant effect on the accurate determination of creatinine; higher concentrations (30 g/liter) had inhibitory effects on the test. Analytical recovery of creatinine added to either normal or abnormal sera averaged 102%. When results of this procedure and of the standard direct Jaffé test were compared, the latter were significantly higher. Unlike the Jaffé method, the present method of determining creatinine is rapid (about 10 min per test), subject to few or no interfering substances, and requires no serum deproteinization.

Submitted on April 9, 1975
Accepted on May 21, 1975

The following articles in journals at HighWire Press have cited this article:

				C. M. Cobbaert, H. Baadenhuijsen, and C. W. Weykamp Prime Time for Enzymatic Creatinine Methods in Pediatrics Clin. Chem., March 1, 2009; 55(3): 549 - 558. [Abstract] [Full Text] [PDF]

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