Long-Term stability of 6-hydroxymelatonin sulfate in 24-h urine samples stored at -20 degrees C.
The purpose of the present feasibility study was to determine whether the concentration of 6-hydroxymelatonin sulfate (6-OHMS) remains stable in urine samples stored over at least 15 yr. To test this, 117 twenty-four-hour urine samples were analyzed, which were obtained from healthy children ages 8 to 9 yr within the periods of 1985-1987,1991-1993, and 1997-1999. 6-OHMS concentrations were determined by enzyme-linked immunosorbent assay. The statistical analyses clearly indicate that the concentration of 6-OHMS remains stable for at least 15 yr if the urine is stored at -20 degrees C.
Griefahn
B
B
Institute for Occupational Physiology at the University of Dortmund, Federal Republic of Germany. griefahn@arb-phys.uni-dortmund.de
Remer
T
T
Blaszkewicz
M
M
Bröde
P
P
D002648:Child; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005615:Freezing; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine*; D013048:Specimen Handling; D013997:Time Factors
D008550:Melatonin; C012365:6-hydroxymelatonin