Glycerol prevents loss of immunoreactive follicle-stimulating hormone and luteinizing hormone from frozen urine.
First morning urine samples were collected from both menstruant and post-menopausal women and stored at -25 degrees C. Immunoreactive FSH disappeared from these samples (t1/2 = 30 days), ultimately stabilizing at about 20% of the initial value. The loss was more rapid at -20 degrees C and less rapid at -55 degrees C and +4 degrees C. Immunoreactive LH was also lost from frozen urine, but more slowly than FSH. The addition of glycerol to urine (0.52 mol/l) stored at -25 degrees C prevented loss of immunoreactive FSH and LH for at least 105 days.
D004355:Drug Stability; D005260:Female; D005640:Follicle Stimulating Hormone / Q000652:urine*; D005615:Freezing; D005990:Glycerol / Q000494:pharmacology*; D006801:Humans; D007986:Luteinizing Hormone / Q000652:urine*; D008593:Menopause; D011309:Preservation, Biological; D011863:Radioimmunoassay
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D005990:Glycerol