The Effect of Storage on Serum Oxalate Values

Urinary and Plasma Oxalate during Ingestion of Pure Ascorbic Acid: A Re-Evaluation

“…(table III). This apparent contradiction is explained by the increase in plasma/serum oxalate values which have been shown to occur during storage [Maguire et al, 1981], The serum samples of the initial Redoxon study [Hatch et al, 1980] were stored at -20 °C for up to 10 weeks before being analysed.…”

“…Plasma oxalate was determined by the method of Hatch et al [1977] with the mod ifications outlined by Maguire et al [1981]. Plasma ascorbate was determined by the method of Denson and Bowers [ 1961], plasma and urinary urate by the method of Praetorius and Poulsen [1953], and urinary citrate as described by Welshman and McCambridge [1973].…”

Chemiluminescent measurement of oxalate in serum by detection of hydrogen peroxide generated through oxalate oxidase

“…This disease, characterized by increased urinary excretion of oxalate, leading to recurrent urolithiasis and nephrocalcinosis, is a rare autosomal recessive inborn error of glyoxylate metabolism due to a functional defect of a liver enzyme, alanine glyoxylate aminotransferase (1). The oxalate assay in serum is difficult because of the low oxalate concentration levels, interfering substances and problems due to in vitro generation of oxalate (1)(2)(3). Through the years, many methods have been described for the determination of oxalate in serum.…”

Serum Oxalate in Chronic Renal Failure

“…Serum was separated from blood within 30 min of collection to avoid changes in the serum level (8). The serum was made alkaline by the addition of 3 ml 0.1 Mbicarbonate buffer.…”