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Test Code C1ES C1 Esterase Inhibitor Antigen, Serum

Important Note

After specimen collection, place the tube on wet ice and send to the laboratory immediately.

Additional Codes

Epic Ordering Code LAB3040936
NBS code LBC13318
Service code 36934

Reporting Name

C1 Esterase Inhibitor Antigen, S

Specimen Type

Serum


Specimen Required


Patient Preparations:

Fasting: 12 hours, preferred but not required.

Supplies: Sarstedt Aliquot Tube, 5 mL (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 and aliquot serum into plastic vial.

3. Freeze specimen within 30 minutes.


National University Hospital-Singapore Note:

NUH Outreach Laboratories:
Specimen Requirements
Submit only one of the following:
Preferred: Red Top
Acceptable: Gold Top
Processing Requirements
Centrifuge and aliquot serum into a plastic vial. 
Specimen type: Serum
Volume: 1 mL
Storage/transport requirements: Refrigerated

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Frozen (preferred) 28 days
  Refrigerated  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Method Name

Nephelometry

Day(s) Performed

Monday through Friday

Report Available

2 to 5 days
National University Hospital-Singapore Note:

Please note that this is a referral test requiring transport to the external testing facility and an additional 3-5 days is required.

Reference Values

19-37 mg/dL

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Diagnosis of hereditary angioedema

 

Monitoring levels of C1 esterase inhibitor in response to therapy

CPT Code Information

83883

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C1ES C1 Esterase Inhibitor Antigen, S 4477-6

 

Result ID Test Result Name Result LOINC Value
C1ES C1 Esterase Inhibitor Antigen, S 4477-6

Secondary ID

8198

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.
National University Hospital-Singapore Additional Information:

Last updated 03/07/2026