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Test ID C1INF C1 Esterase Inhibitor, Functional, Serum

Specimen Required

Patient Preparation: Fasting, preferred but not required

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice.

2. Centrifuge at 4° C and aliquot serum into a 5-mL plastic vial.

3. Freeze specimen within 30 minutes.

Useful For

Diagnosing hereditary angioedema


Monitoring response to C1 esterase inhibitor replacement therapy

Method Name

Enzyme Immunoassay (EIA)

Reporting Name

C1 Esterase Inhib, Functional, S

Specimen Type

Serum Red

Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen 28 days

Reference Values

>67% normal (normal)

41-67% normal (equivocal)

<41% normal (abnormal)

Day(s) Performed


Report Available

3 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
C1INF C1 Esterase Inhib, Functional, S 48494-9


Result ID Test Result Name Result LOINC Value
C1INF C1 Esterase Inhib, Functional, S 48494-9