Time-resolved immunofluorometric assay and specimen storage conditions for measuring urinary gonadotropins.
We optimized storage conditions and validated a sensitive immunofluorometric assay (IFMA) for urinary gonadotropins. Assay linearity and parallelism for luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was observed to 0.04 IU/L. Urinary LH and FSH were unaffected by changes of osmolarity from 0.5 to 3.0 mOsm/kg, and from pH 4.5 to 10.5. Serum and urine measurements of the hormones correlated well over a wide range of values: for LH, R2 = 0.94, P < 0.01; for FSH, R2 = 0.71, P < 0.01 (n = 304). Preservation of urine with glycerol (70 mL/L) and storage at -20 degrees C yielded > 80% recovery of LH and FSH after 51 weeks; this was comparable with recovery for acetone extracts of urine. Untreated urine showed loss of activity by 4 weeks of storage. Preserving urine specimens with glycerol is a simple method of storage for longitudinal study and compares favorably with acetone extraction. IFMAs can measure urinary gonadotropins reproducibly over a wide range of pH and osmotic conditions.
Saketos
M
M
Mount Sinai School of Medicine, Department of Obstetrics, Gynecology and Reproductive Science, New York, NY 10029.
Sharma
N
N
Adel
T
T
Raghuwanshi
M
M
Santoro
N
N
D000328:Adult; D004355:Drug Stability; D005260:Female; D015200:Fluoroimmunoassay / Q000379:methods*; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000652:urine*; D005615:Freezing; D005990:Glycerol; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011247:Pregnancy; D012016:Reference Values; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D005990:Glycerol