A comparison of analytic procedures for measurement of fractional dextran clearances

MH Hemmelder, PE de Jong, D de Zeeuw*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)

Abstract

Fractional dextran clearances have been extensively used to study glomerular size selectivity. We report on an analysis of different laboratory procedures involved in measuring fractional dextran clearances. The deproteinization of plasma samples by 20% trichloroacetic acid (TCA) revealed a protein contamination of 0.2% +/- 0.3%, whereas both 5% TCA and zinc sulfate deproteinization revealed a significantly higher remaining sample protein content (2.5% +/- 0.4% and 3.4% +/- 0.1%, respectively). Only zinc sulfate revealed incomplete deproteinization of urine samples (0.6% +/- 0.2%). Dextran recovery in plasma and urine supernatants was significantly lower after 5% TCA and zinc sulfate deproteinization when compared with 20% TCA deproteinization. Gel permeation chromatography (GPC) and high-performance liquid chromatography (HPLC) showed a variance of calibration smaller than 5% over 1 year. The use of 3 different sets of standard dextrans revealed significant differences in calibration. GPC and HPLC followed by anthrone assay showed a comparable variance in dextran concentration in plasma, from 3 to 6 nm (14% to 25%), whereas the variance in urine was lower for the GPC and anthrone assay, especially from 5.4 to 6 nm (23% to 43% versus 50% to 78%). HPLC and online refractometry showed the lowest variance of dextran concentration in plasma, from 3 to 6 nm (

Original languageEnglish
Pages (from-to)390-403
Number of pages14
JournalJournal of Laboratory and Clinical Medicine
Volume132
Issue number5
Publication statusPublished - Nov-1998

Keywords

  • GLOMERULAR-FILTRATION BARRIER
  • CONVERTING-ENZYME-INHIBITION
  • MINIMAL CHANGE NEPHROPATHY
  • DIABETIC NEPHROPATHY
  • NEPHROTIC HUMANS
  • SIZE-SELECTIVITY
  • MEMBRANOUS NEPHROPATHY
  • CHARGE SELECTIVITY
  • VOLUME EXPANSION
  • RENAL-DISEASE

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