Time-resolved immunofluorometric assay of 34-kDa somatomedin-binding protein.
In this time-resolved immunofluorometric assay for the 34-kDa somatomedin-binding protein (SmBP), affinity-purified polyclonal antibodies are used, along with solid-phase separation of bound and free analyte. The first antibody is bound to polystyrene microtiter wells; the second is labeled with europium(III) chelate. The detection limit of the method is 0.25 microgram/L, much lower than that (about 8 micrograms/L) for radioimmunoassay. By immunofluorometric assay, SmBP is detectable, and could be accurately quantified, in the serum of all 88 individuals we tested, whereas by radioimmunoassay a third of the samples had concentrations below the detection limit. When SmBP was detectable by both methods, the concentrations measured by the two techniques correlated well (r = 0.98).
D002352:Carrier Proteins / Q000097:blood*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D008297:Male; D011247:Pregnancy; D011863:Radioimmunoassay; D012016:Reference Values
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins