Order Code UE3 Estriol, Unconjugated, Serum
Reporting Name
Estriol, Unconjugated, SUseful For
As an adjunct biomarker in the prenatal diagnosis of disorders of fetal steroid metabolism, including Smith-Lemli-Opitz syndrome (1,2) and X-linked ichthyosis (placental sulfatase deficiency disorders)
Evaluating primary or secondary fetal adrenal insufficiency after excluding other rare single gene defects, including aromatase deficiency, 17 alpha-hydroxylase deficiency and/or various forms of congenital adrenal hyperplasia
Performing Laboratory

Specimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.6 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 90 days |
Reference Values
Males: <0.07 ng/mL
Females: <0.08 ng/mL
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Day(s) Performed
Monday through Friday
CPT Code Information
82677
Method Description
The instrument used is the Beckman Coulter UniCel DxI 800. The Access unconjugated estriol assay is a competitive binding immunoenzymatic assay. A sample is added to a reaction vessel with estriol-alkaline phosphatase conjugate, paramagnetic particles coated with goat anti-rabbit IgG, and polyclonal rabbit anti-estriol. Estriol in the sample competes with estriol-alkaline phosphatase conjugate for a limited number of binding sites on the specific anti-estriol antibody. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then the chemiluminescent substrate Lumi-Phos 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of estriol in the sample. The amount of analyte in the sample is determined by means of a stored, multipoint calibration curve.(Package Insert: Access Unconjugated Estriol Assay. Beckman Coulter, Inc; 2019)
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Immunoenzymatic Assay