Modification of the choriogonadotropin beta-subunit radioimmunoassay for determination of urinary chorigonadotropin. [/sup 125/I tracer technique]

Journal Article · Wed Nov 01 00:00:00 EST 1978 · Clin. Chem.; (United States)

OSTI ID:6340622

McCready, J; Braunstein, G D; Helm, D; Wade, M E

The choriogonadotropin beta-subunit radioimmunoassay has been used extensively to measure human choriogonadotropin in the sera of pregnant women and individuals with trophoblastic and nontrophoblastic tumors. Unmodified, this method cannot be used to measure choriodonadotropin in urine because of interfering substances. We circumvented the non-parallelism between the standards and serial dilutions of urine containing choriogonadotropin by adding pooled urine from men to the standard tubes and limiting the volume of urine to 100 ..mu..l. This modified assay has a sensitivity of 3 int. units/liter of urine and is specific for choriogonadotropin concentrations of 40 int. units/liter of urine. Analytical recovery of choriogonadotropin added to urine ranged from 96 to 105%. The within-assay CV was 7.6%; the between-assay CV was 11.8%. Concentrations of choriogonadotropin in concurrently collected serum and urine samples from pregnant women correlated well. The test can be performed within 24 h by using the double-antibody method for separating bound from free hormone, or in 3 h with a dioxane method. The assay is about 20-fold more sensitive than the 2-min or 2-h slide and tube pregnancy tests, and seven- to 12-fold more sensitive than the radioreceptor assay.

• Research Organization: Cedars-Sinai Medical Center, Los Angeles, CA
• OSTI ID: 6340622
• Journal Information: Clin. Chem.; (United States), Vol. 24:11
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GONADOTROPINS
RADIOIMMUNOASSAY
BLOOD SERUM
FETAL MEMBRANES
IODINE 125
NEOPLASMS
PREGNANCY
SENSITIVITY
TRACER TECHNIQUES
URINE
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
PEPTIDE HORMONES
PITUITARY HORMONES
RADIOASSAY
RADIOISOTOPES
WASTES
550601* - Medicine- Unsealed Radionuclides in Diagnostics