title: Immunoturbidimetry of serum apolipoproteins A-I and B on the Cobas Bio centrifugal analyzer: method validation and reference values.
abstract: We describe an immunoturbidimetric assay for estimating the concentration of apolipoproteins (apo) A-I and B in serum with a Cobas Bio centrifugal analyzer. Several analytical variables were studied: pH, temperature, wavelength, reaction time, sample pretreatment, antisera dilution, concentration of NaCl, phosphate buffer, and PEG 6000; a good optical response was obtained with small volumes of sample and antisera. Imprecision was low, with intrarun coefficient of variance (CV) from 1.1 to 2.8% and interrun CV from 1.8 to 3.2%. We demonstrated a good correlation between our method and radial immunodiffusion for apo A-I (r = 0.975) and apo B (r = 0.980). Reference values were calculated from a sample of 494 healthy subjects, and separate intervals for the ratio of apo A-I to apo B in gender and age subgroups were established.
authors.affiliation: Laboratorio de Bioquímica, Hospital Txagorritxu, Vitoria, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Eugui
authors.forename: M J
authors.initials: MJ
authors.lastname: Logroño
authors.forename: R
authors.initials: R
authors.lastname: Ruiz
authors.forename: C
authors.initials: C
authors.lastname: Zugaza
authors.forename: J L
authors.initials: JL
authors.lastname: Mirabel
authors.forename: C
authors.initials: C
authors.lastname: Martínez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001054:Apolipoproteins A / Q000097:blood*; D001055:Apolipoproteins B / Q000097:blood*; D002498:Centrifugation; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010710:Phosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D012016:Reference Values; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature
chemical_list: D001054:Apolipoproteins A; D001055:Apolipoproteins B; D010710:Phosphates; D011092:Polyethylene Glycols; D012965:Sodium Chloride