Oestradiol (Blood)

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

E20

Test Code (Numeric Code)

3879

Laboratory Handling

Sample Stability

24 hours at 20-25 °C, 2 days at 2-8 °C, 6 months at -20 °C.

Synonyms

17 beta-oestradiol, E2, Estradiol, E2, E20,

Turnaround Time

3 hours

Specimen Type

• Plasma
• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin PST- Gel (Light Green Cap)

Acceptable

• Lithium Heparin - Non-gel (Green Cap)
• Plain (Red Top)
• SST II (Gold Cap)

Preferred Sample Volume (ml)

4.5

Minimum Sample Volume (ml)

3.5

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin PST- Gel (Light Green Cap)

Acceptable

• Lithium Heparin - Non-gel (Green Cap)
• Plain (Red Top)

Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

0.5 mL Paediatric Microtainer PST Blood (Preferred)
0.5 mL Paediatric Microtainer Plain Blood
0.5 mL Paediatric Microtainer Heparin Blood

Aliquot Instructions

Sample Type

• Serum
• Plasma

Minimum Volume (ml)

0.2

Transport to Lab

Chilled (2 - 8 degrees Celsius)
Frozen

Additional Referral/Aliquot Information

Outside laboratories separate off serum and forward to LabPlus laboratory.
Send a separated PST or SST tube, or at least 200uL serum/plasma aliquot.
Transport at 4°C, or frozen if time delay is likely to be greater than 2 days.

Test Method

Performed in: LabPlus Automation
Principle: Competitive type immunoassay with chemiluminescence detection
Reagents: Roche assay
Analyser: Roche Cobas

Limitations / Interference

Interference with Oestradiol Method by Chemotherapy Drug Fulvestrant (Faslodex):
Fulvestrant is an oestrogen receptor blocking drug used in treatment of breast cancer with close structural similarity to oestradiol . This drug has been found to cause marked interference in the immunoassay used at LabPlus (Roche Cobas).
Similar interference has also been identified in other oestradiol immunoassays used in Auckland. The degree of interference varies by oestradiol concentration, so no factor or baseline can be applied.
Fulvestrant is not currently funded by Pharmac. It is available under Section 29 but is currently seldom used in New Zealand. In the unlikely event that a patient may be taking this drug please be aware of this interference.
If you wish to discuss further please contact a Chemical Pathologist via the contact information below.

Interference with many Immunoassays by Biotin:
Most immunoassays (e.g. TSH, fT4, ferritin) used at LabPlus incorporate biotin into the formulation of the assay. The potential for significant interference in these assays has been identified in patients taking large doses of biotin (at least 10-50mg/day). The interference can either cause false elevation or false reduction depending on the assay.

Very small doses commonly used in multivitamins do not have any significant effect. Because of the short half-life of biotin in plasma (about 1-2 hrs) separation from dosing by at least 8hr is also recommended .

If you wish to discuss further please contact a Chemical Pathologist via the contact information below.

Uncertainty of Measurement

7% below level of 350 pmol/L
5% above level of 750 pmol/L

Contact Information