Stockgrand Ltd. Monitoring the biological clock. The biological clock.


Melatonin levels

Why measure melatonin or aMT6s?

  • To investigate circadian rhythm disorder (e.g. sleep problems of blindness, and old age, advanced and delayed sleep phase insomnia, non-24 hour sleep wake problems, shift work, jet lag).
  • To investigate exposure to light at night (hypothesised to have detrimental effects on health).
  • To precisely define circadian phase for the purposes of timed treatment.
  • To investigate the normal function of the biological clock.
  • To investigate normal pineal function and pineal dysfunction, for example pineal tumors, research into certain cases of abnormal puberty and other endocrine abnormalities.

When and where to measure melatonin?

Depending on the precision of measurment required:

  • hourly or less for 24h (plasma)
  • hourly or less for 24h (saliva)
  • 3-4 hourly (longer during sleep period)
    for at least 24 h, preferably for 48 h or
    longer (6-sulphatoxymelatonin, urine)
Melatonin suppression as a function of wavelength and irradience.

Techniques to measure melatonin

  • Gas-chromatography mass spectrometry (GCMS) or GCMS validated radioimmunoassay (RIA) or Enzyme-Linked Immunosorbent Assay (ELISA). GCMS validated RIA is used by Stockgrand Ltd.
  • Other techniques include High performance liquid chromatography (HPLC) and Fluorimetry.

A selection of Stockgrand's methodological references are available.