Automated Reaction-Rate Method for Determination of Serum Creatinine with the CentrifiChem

Abstract

An automated kinetic method to determine creatinine in serum with the Jaffé reaction is described. The method does not require deproteinization or adsorption of creatinine on Fuller's earth or ion-exchange resin. A maximum of 29 serum samples, standards, and control sera can be assayed in less than 1.5 min. Interferences by most of the known Jaffé-positive serum constituents were studied and minimized by optimal selection of the time interval during which the reaction rate was measured. Results of precision studies and correlation with a manual method requiring adsorption of creatinine on ion-exchange resin are reported. Spectroscopic data suggest that the product of reaction between picrate and creatinine is a 1:1 adduct of the two starting molecules.