Folate

Alternative names, keywords

Folic acid

(click here for B₁₂)

Samples required

● Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

Avoid haemolysis.

Test indications

Factors affecting test performance/ results

Haemolysis may significantly increase folate values due to high concentrations of folate in red blood cells. Haemolysed samples are therefore not suitable for use in this assay.

It is contraindicated to measure samples of patients receiving therapy with certain pharmaceuticals, e.g. methotrexate or leucovorin, because of the cross-reactivity of folate binding protein with these compounds.

Samples with extremely high total protein concentrations (e.g. patients suffering from Waldenström’s macroglobulinemia) are not suitable for use in this assay.

Samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration.

In rare cases, interference due to extremely high titres of antibodies to streptavidin and ruthenium can occur.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

> 1.9 µg/L
_{Source:  in-house data}

Turnaround time

24 hours (weekdays)

Enquiries

Biochemistry (Automation)