Measurement of urinary oxalate by grain sorghum leaf oxalate oxidase immobilized to affixed alkylamine glass beads

Abstract

Oxalate in urine was measured by grain Sorghum leaf oxalate oxidase conjugated to alkyl amine glass beads affixed in a beaker. The minimum detection limit was 0.05 mM/L in urine. Recovery of added oxalate in urine was 80.5% and within and between assay, coefficients of variation (CV) were <4% and <5.5%, respectively. Urinary oxalate values obtained by the present method showed a good correlation (r = 0.947) with those by Sigma kit method. The method is not only free from tedious handling of free glass beads and Cl⁻ interference, but also has longer stability and reusability of immobilized enzyme compared to that of barley root and forage Sorghum leaf.