Determination of transcortin in serum by polyethylenglycol enhanced immunonephelometry. A comparison with equilibrium dialysis and radioimmunoassay.
A method for immunonepholometric determination of transcortin has been developed. It is based upon a polyethylenglycol (PEG) enhanced immunonephelometric response using a commercial transcortin antiserum in the assay. It was found that pretreatment of the serum samples with 10% (w/v) PEG 6000 was a necessity in order to obtain satisfactory low blank values. The immunonephelometric assay showed a good correlation with transcortin concentrations as calculated from cortisol binding experiments (r = 0.9501, n = 26). The intraassay coefficient of variation for a standard serum was found to be 3.2% (n = 50) and for a pregnancy serum pool 2.6% (n = 50). The interassay coefficient of variation in ten consecutive analyses of thirteen samples was found to be 7.4%. The sensitivity allows detection of transcortin in 5 microliters of serum. The average concentration in male serum was 35 mg/l (n = 55), in female serum 36 mg/l (n = 55) and in serum from third trimester pregnant women 81 mg/l (n = 30) which agrees with the results in previously published reports.
Eriksson
C G
CG
Department of Obstetrics and Gynecology, Karolinska sjukhuset, Stockholm, Sweden.
Eneroth
P
P
D003956:Dialysis; D005260:Female; D006801:Humans; D007158:Immunologic Techniques; D008297:Male; D009391:Nephelometry and Turbidimetry / Q000379:methods; D011092:Polyethylene Glycols; D011863:Radioimmunoassay / Q000379:methods; D012016:Reference Values; D014156:Transcortin / Q000032:analysis*
D011092:Polyethylene Glycols; D014156:Transcortin