Enzymic determination of citrate in serum and urine, with use of the Worthington "ultrafree" device.

Journal Article (Journal Article)

We describe an enzymic method for conveniently measuring citrate in serum or urine. Interfering enzyme proteins are removed by a disposable ultrafilter ("Ultrafree"; Worthington Diagnostics), obviating the need for hazardous protein precipitants. A 50 mmol/L Tris buffer adequately controls pH, no lactate dehydrogenase is necessary in the reagents, and the reaction of citrate catalyzed by citrate lyase (EC is complete in 2-3 min. Within-run and day-to-day coefficients of variation were 7.5% and 5.4%, respectively. Serum citrate concentrations for 20 apparently healthy persons ranged from 0.08 to 0.17 mmol/L (mean 0.12, SD 0.03). Urinary citrate excretion by six normal volunteers ranged from 2.2 to 4.4 mmol/24 h. We observed no detectable changes in citrate in whole blood stored at room temperature for 90 min or longer. Overall, the method is faster and less hazardous than other methods for citrate that require protein precipitation.

Full Text

Duke Authors

Cited Authors

  • Tompkins, D; Toffaletti, J

Published Date

  • January 1, 1982

Published In

Volume / Issue

  • 28 / 1

Start / End Page

  • 192 - 195

PubMed ID

  • 7055912

International Standard Serial Number (ISSN)

  • 0009-9147


  • eng

Conference Location

  • England