Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Selenium is an essential trace element and is a cofactor for numerous enzymes, such as the glutathione peroxidase family of enzymes. Measurement of selenium in serum is used to give an indication of body selenium status. Selenium deficiency is usually caused by severely compromised intestinal function, total parenteral nutrition and gastrointestinal bypass surgery. Selenium is a negative acute phase reactant and therefore serum levels should be assessed at least two weeks after the acute phase has subsided.
Specimen container paediatric:
Serum trace element tube; Navy blue top with red-striped label – preferred sample
White top plain tube (glass)
Specimen container adult:
Serum trace element tubeNavy blue top with red-striped label
Available on request from Blood Sciences reception at both Freeman and RVI sites
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Grossly haemolysed samples are unsuitable for analysis.
Transport to laboratory immediately for rapid separation of serum from red blood cells.
Sample stability:
Serum samples are stable at 2-4°C for up to 6 weeks or at -20°C indefinitely.
Transport requirements:
Ambient temperature.
Quality assurance:
Trace Element Quality Assurance Scheme (TEQAS) for Trace Elements
Reference ranges:
| Age | Selenium (µmol/L) |
|---|---|
| <7 days | 0.33 – 0.97 |
| 7 days to 5 months | 0.51 – 1.12 |
| 5 months to 1 year | 0.60 – 1.29 |
| 1 year to 14 years | 0.75 – 1.46 |
| 14 years | 0.66 – 1.57 |
Factors affecting result:
Failure to adhere to correct specimen collection procedures can cause abnormal results due to specimen (dust) contamination, which can lead to misinterpretation and misdiagnosis.