Albumin adsorption onto surfaces of urine collection and analysis containers

• Type of Material: Article
• Authors: Mary K. Robinson, Centers for Disease Control & Prevention; Samuel P. Caudill, Centers for Disease Control & Prevention; David D Koch, Emory University; James C Ritchie, Emory University; Glen Hortin, Quest Diagnostics; John H. Eckfeldt, University of Minnesota; Sverre Sandberg, Haukeland University; Desmond Williams, Centers for Disease Control & Prevention; Gary Myers, American Association for Clinical Chemistry; W. Greg Miller, Virginia Commonwealth University
• Language: English
• Date: 2014-04-20
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 Elsevier B.V. Published by Elsevier B.V. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1016/j.cca.2014.01.035
• Title of Journal or Parent Work: Clinica Chimica Acta
• ISSN: 0009-8981
• Volume: 431
• Start Page: 40
• End Page: 45
• Keywords: Urine containers; Medical Laboratory Technology; Albumin adsorption; Life Sciences & Biomedicine; Science & Technology; HUMAN SERUM-ALBUMIN; Urine albumin
• Research Categories: Health Sciences, Pathology; Health Sciences, Medicine and Surgery

Abstract

Background: Adsorption of albumin onto urine collection and analysis containers may cause falsely low concentrations. Methods: We added 125 I-labeled human serum albumin to urine and to phosphate buffered solutions, incubated them with 22 plastic container materials and measured adsorption by liquid scintillation counting. Results: Adsorption of urine albumin (UA) at 5-6. mg/l was < . 0.9%; and at 90. mg/l was < . 0.4%. Adsorption was generally less at pH. 8 than pH. 5 but only 3 cases had p. < . 0.05. Adsorption from 11 unaltered urine samples with albumin 5-333. mg/l was < . 0.8%. Albumin adsorption for the material with greatest binding was extrapolated to the surface areas of 100. ml and 2. l collection containers, and to instrument sample cups and showed < . 1% change in concentration at 5. mg/l and < . 0.5% change at 20. mg/l or higher concentrations. Adsorption of albumin from phosphate buffered solutions (2-28%) was larger than that from urine. Conclusions: Albumin adsorption differed among urine samples and plastic materials, but the total influence of adsorption was < . 1% for all materials and urine samples tested. Adsorption of albumin from phosphate buffered solutions was larger than that from urine and could be a limitation for preparations used as calibrators.