Pathology tests database

Sample and container requirements

Serum Lithium Heparin Plasma (paediatrics only)

Minimum volume required

Special requirements

None

Patient preparation

Samples from patients receiving high biotin doses (i.e. >5 mg/day) should be taken at least 8 hours post-dose.

Sample viability

Turnaround time

2 days

Reference range

2.4 - 6.0 pmol/L (Source: Abbott Diagnostics) In pregnancy: Trimester 1: 3.52 – 6.22 pmol/L Trimester 2: 3.41 – 5.78 pmol/L Trimester 3: 3.33 – 5.59 pmol/L (Source: Stricker et al., 2007, doi: 10.1530/EJE-07-0249)

Clinical guidance

Free T3 plays an important role in maintenance of the euthyroid state and assists in the diagnosis of thyroid dysfunction. Please refer to LabTestsOnlineUK to learn more about fT3. https://labtestsonline.org.uk/tests/ft3

Notes

fT3 analysis is only available in certain circumstances.