title: Comparison of five methods for determination of total plasma protein concentration.
abstract: Quantitation of exact total protein content is often a key step and is common to many applications in general biochemistry research and routine clinical laboratory practice. Before embarking on any type of protein analysis, particularly comparative techniques, it is important to accurately quantitate the amount of protein in the sample. In order to assess the quality of total protein estimation results, five methods were tested and were applied to the same pooled plasma sample. For this aim, Bradford (Coomassie Brilliant Blue), Lowry (Folin-Ciocalteau), Biüret, Pesce and Strande (Ponceau-S/TCA), and modified method of Schaffner-Weismann (Amido Black 10B) were used. The last two methods employ simultaneous precipitation of proteins with the acid containing dye solutions followed by dissolution of precipitate in a NaOH solution. It is shown that each assay has advantages and disadvantages relative to sensitivity, ease of performance, acceptance in literature, accuracy and reproducibility/coefficient of variation. All of the methods tested show a CV %<6. Besides pooled plasma, a known concentration of human serum albumin was also analyzed and discussed by means of standardization of plasma total protein content.
authors.affiliation: Ege University, Faculty of Science, Biochemistry Department, 35100-Bornova, Izmir, Turkey. burcu.okutucu@ege.edu.tr
authors.forename: Burcu
authors.initials: B
authors.lastname: Okutucu
authors.forename: Ayşşe
authors.initials: A
authors.lastname: Dinçer
authors.forename: Omer
authors.initials: O
authors.lastname: Habib
authors.forename: Figen
authors.initials: F
authors.lastname: Zihnioglu
mesh_terms: D000580:Amido Black; D001391:Azo Compounds; D001738:Biuret Reaction; D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D001798:Blood Proteins / Q000032:analysis*; D004396:Coloring Agents; D006801:Humans; D007202:Indicators and Reagents; D008982:Molybdenum; D012015:Reference Standards; D012016:Reference Values; D012394:Rosaniline Dyes; D012709:Serum Albumin / Q000032:analysis / Q000592:standards; D017973:Tungsten Compounds
chemical_list: D001391:Azo Compounds; D001798:Blood Proteins; D004396:Coloring Agents; C029556:Folin's phenol reagent; D007202:Indicators and Reagents; D012394:Rosaniline Dyes; D012709:Serum Albumin; D017973:Tungsten Compounds; D008982:Molybdenum; C004692:coomassie Brilliant Blue; D000580:Amido Black; C032756:ponceau S