Testing Laboratory
Auckland Te Toka Tumai | Auckland HospitalDepartment
Immunology
Delphic Registration Code (Alpha Code)
INHA
Test Code (Numeric Code)
7232
Laboratory Handling
Phlebotomy
All specimens requiring the C1 inhibitor functional assay should only be collected between 8am AND 2.30pm MON - FRI. At the time of collection, place an "Urgent" label on the form and indicate below the sticker "C1 Esterase". Contact ICHEM on 09 307 49 49 ext 22113 to inform the laboratory of the collect. It is crucial that the laboratory staff separate the sample within 1 hour of collection and freeze the serum at -20°C
Transport
Ambient
Separating
C1 Inhibitor Functional Assay needs to be separated and frozen within an hour of collection. All C1 inhibitor requests also require an aliquot for C4.
Laboratory
LabPlus Immunochemistry
Test Adds Requirement
Test adds of other complement assays on this request is not recommended.
Sample Stability
-20°C for one month - repeat freeze thaw cycles should be avoided. 2-8°C for 8 days if this is not reflexed from the C1 inhibitor functional assay.
Associated Tests
Synonyms
C1 esterase
C1 antigenic levels
C1 esterase antigenic levels
Turnaround Time
2 weeks
This is a reflex test for an abnormal C1 inhibitor function result.
Specimen Type
- Serum
Specimen Requirements
Tube/Container Type:
Preferred
- SST II (Gold Cap)
Acceptable
- Plain (Red Top)
Preferred Sample Volume (ml)
3.5
Minimum Sample Volume (ml)
1
No of Samples Required
1
Paediatric Specimen Requirements
Tube/Container Type:
Preferred
- SST II (Gold Cap)
Acceptable
- Plain (Red Top)
Preferred Sample Volume (ml)
1
Minimum Sample Volume (ml)
1
Pre-testing Requirements
Screening for hereditary or acquired C1 inhibitor deficiency will be undertaken with a functional C1 inhibitor assay and a C4 assay. If C1 inhibitor function is reduced, the C1 inhibitor level assay will be added to testing.
Last updated: 17/07/2026