Test Overview

Test Methodology


Test Usage

Investigating an undetectable total complement level and investigating individuals with increased susceptibility to bacterial infections. Patients with C5 deficiency haved a marked increase in the incidence of autoimmune disorders and have increased susceptibility to bacterial infection. Congenital deficiency patients have values near zero.

Reference Range*

10.6 - 26.3 mg/Dl

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

The molecule may be dysfunctional with normal values but with ineffective white cell chemotaxis.

Test Details

Days Test Performed

Monday - Saturday

Analytic Time

2 - 4 days

Soft Order Code


MiChart Code

C5 Complement, Antigen



Complement C5
Fifth Component of Complement

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Laboratory Reference

Mayo C5AG (9266)

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Specimen Requirements

Offsite Collection Instructions

Collect blood in a red top or SST tube from a fasting patient. Centrifuge, aliquot serum into plastic vial and freeze.

Special Handing

Fasting specimen.


Yellow Top Tube

Normal Volume

1 mL serum

Minimum Volume

0.5 mL serum

Additional Information

The Complement, Total Hemolytic (CH50) assay should be used as a screen for suspected complement deficiencies before ordering individual complement component assays. A deficiency of an individual component of the complement cascade will result in an undetectable total complement level. Test sent to Mayo Medical Laboratories.

Billing Information

Fee Codes

CPT Code




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