title: Urine protein concentration estimation for biomarker discovery.
abstract: Recent advances have been made in the study of urinary proteomics as a diagnostic tool for renal disease and pre-eclampsia which requires accurate measurement of urinary protein. We compared different protein assays (Bicinchoninic acid (BCA), Lowry and Bradford) against the 'gold standard' amino-acid assay in urine from 43 women (8 non-pregnant, 34 pregnant, including 8 with pre-eclampsia). BCA assay was superior to both Lowry and Bradford assays (Bland Altman bias: 0.08) compared to amino-acid assay, which performed particularly poorly at higher protein concentrations. These data highlight the need to use amino-acid or BCA assays for unprocessed urine protein estimation.
authors.affiliation: Division of Women's Health, King's College London, UK. Electronic address: hiten.mistry@kcl.ac.uk.
authors.forename: Hiten D
authors.initials: HD
authors.lastname: Mistry
authors.affiliation: Division of Women's Health, King's College London, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Bramham
authors.affiliation: Centre of Excellence for Mass Spectrometry, Proteomics Facility, Institute of Psychiatry, King's College London, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Weston
authors.affiliation: Centre of Excellence for Mass Spectrometry, Proteomics Facility, Institute of Psychiatry, King's College London, UK.
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: Ward
authors.affiliation: Centre of Excellence for Mass Spectrometry, Proteomics Facility, Institute of Psychiatry, King's College London, UK; Proteomics Core Facility, The Institute of Cancer Research, London, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Thompson
authors.affiliation: Division of Women's Health, King's College London, UK.
authors.forename: Lucy C
authors.initials: LC
authors.lastname: Chappell
keywords: Protein concentration assays; Proteomics; Urine