Abstract
Saliva samples are easy to collect and are applicable for home-sampling, e.g. when studying HPA-axis dynamics to characterize diurnal cortisol profiles and the cortisol awakening response. However, the storing and transport conditions might be critical in the home-sampling approach. Here, we tested the stability of saliva cortisol in samples stored at different temperatures and after repeated thawing-freezing cycles when measured with an Enzyme Immuno Assay (EIA). Thirteen healthy volunteers, six women and seven men, mean age 31 (range 26-49) years collected saliva either in the morning hours (08:00-10:00 h) or before lunch (11:00-12:00 h). Storage at six different conditions were tested: Storage at - 18°C, - 4°C, 4°C and room temperature for 72 h. One condition tested was at - 18°C for 72 h and then kept in an envelope for 72 h with a freezing element in room temperature surroundings where after it was stored at - 80°C. The last tube was stored directly at - 80°C and served as the 'gold standard'. The saliva samples were assayed using Salivary Cortisol Diagnostic EIA. Differences in cortisol measurements between each of the five conditions and the 'gold standard' (- 80°C) were evaluated by one-sample t-test. No significant differences were observed. This indicates that an EIA method can be used reliably when measuring salivary cortisol samples obtained by home-sampling including a postal delivery.
| Original language | English |
|---|---|
| Journal | Scandinavian Journal of Clinical & Laboratory Investigation |
| Volume | 75 |
| Issue number | 1 |
| Pages (from-to) | 92-5 |
| Number of pages | 4 |
| ISSN | 0036-5513 |
| DOIs | |
| Publication status | Published - 1 Jan 2015 |
Keywords
- Adult
- Cryopreservation
- Enzyme-Linked Immunosorbent Assay
- Female
- Humans
- Hydrocortisone
- Male
- Middle Aged
- Saliva