Protein determination in cerebrospinal fluid by protein dye-binding assay.
In this study, Coomassie brilliant blue (CBB) and pyrogallol red/molybdate (PRM) protein dye-binding assays for total protein determination in cerebrospinal fluid (CSF) are compared. Using human albumin (HA) as a protein calibrator, protein concentration in CSF samples (n = 73) ranged from 55-1960 mg/L (median: 315 mg/L) with the CBB assay, and from 95-2450 mg/L (median: 395 mg/L) with the PRM assay. Linear regression analysis indicated yCBB = 0.824xPRM - 8 (r = 0.99). The discrepancy between the values was investigated by comparing the response of the two assays to different proteins. Compared with HA, the PRM assay showed a more uniform response to human albumin/globulin (A/G) and bovine gamma globulin (G) than did the CBB assay, but it gave high colour yields with bovine myelin basic protein. When CSF was assayed using A/G as a protein calibrator, agreement between the methods improved (yCBB = 0.960xPRM + 0 [r = 0.99]), indicating that comparability is dictated by the choice of protein calibrator. Of the two assays studied, the PRM assay is recommended for CSF protein determination because it gives a more uniform and linear response to human albumin and globulin over a wider working range.
Marshall
T
T
Analytical Biochemistry Group, Institute of Pharmacy, Chemistry and Biomedical Sciences, School of Sciences, University of Sunderland, Sunderland SR1 3RG, UK. tom.marshall@sunderland.ac.uk
Williams
K M
KM
D000818:Animals; D002417:Cattle; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis*; D006801:Humans; D007202:Indicators and Reagents; D011748:Pyrogallol / Q000031:analogs & derivatives*; D012394:Rosaniline Dyes; D013053:Spectrophotometry / Q000379:methods
D002556:Cerebrospinal Fluid Proteins; D007202:Indicators and Reagents; D012394:Rosaniline Dyes; D011748:Pyrogallol; C058731:pyrogallol sulfonphthalein; C004692:coomassie Brilliant Blue