Enzyme immunoassay of thyroxin-binding globulin in dried blood samples on filter paper.
A double-antibody enzyme immunoassay was developed for determination of thyroxin-binding globulin in dried blood samples on filter paper. The measurable concentration range of thyroxin-binding globulin in two 3-mm blood discs was 3.3 to 52 mg/L equivalent of serum (i.e., equivalent to the concentrations in known serum standards). Thyroxin-binding globulin in dried blood samples on filter paper was stable for at least four weeks when kept dry at -20 degrees C, 4 degrees C, or room temperature. The mean coefficients of variation were 6.6% (within assay) and 5.9% (between assays). The concentrations of thyroxin-binding globulin in dried blood samples determined by this method correlated well with those in serum determined by radioimmunoassay (r = 0.95) and by enzyme immunoassay (r = 0.96). This method is applicable for detecting cases of thyroxin-binding globulin deficiency and avoids the false-positive results for neonatal hypothyroidism obtained by measuring thyroxin.
D000293:Adolescent; D000328:Adult; D003890:Desiccation; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood; D007124:Immunoenzyme Techniques; D007231:Infant, Newborn; D008297:Male; D008403:Mass Screening / Q000379:methods; D011247:Pregnancy; D011863:Radioimmunoassay; D013048:Specimen Handling; D013223:Statistics as Topic; D013975:Thyroxine-Binding Proteins / Q000097:blood* / Q000172:deficiency
D013975:Thyroxine-Binding Proteins