Analytic Time

2 - 7 days

MiChart Code
Complement, Total Alternative Path (AH50)
Soft Order Code

Test Updated:


Complement AH50

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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

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Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

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Test Overview

Test Methodology

Enzyme-Linked Immunosorbent Assay (ELISA)

Test Usage

The AH50 assay is a useful screening tool for homozygous deficiencies of Alternative Pathway components including C3, factor I, factor B, properdin, factor H and factor D.

Reference Range

> or = 45% of normal

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

Specimen Requirements

Collection Onsite

Collect specimen in a red top tube from a fasting patient do not use SST tube. Send to Specimen Perocessing in a green bag. Must be spun within 30 minutes.

Collection Offsite

Collect specimen in a red top tube from a fasting patient; do not use SST tube. Centrifuge, aliquot serum into a plastic vial and freeze within 30 minutes.

Yellow Top Tube
Red Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.2 mL serum

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.