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Immunology Laboratory

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Haemolytic Complement Activity - Classical and Alternative Pathways

Also known as: CH50; AP50; CH100; AP100

Test of integrity of classical and alternate lytic pathways of complement. Such conditions are rare and present either with a predisposition to recurrent bacterial infections, especially meningococcal (C5-9, properdin) and pneumococcal infection (C1-4), or with increased susceptibility to immune complex diseases such as SLE (C1-4).

NB If you suspect this condition, we suggest that you discuss this with an Immunologist prior to requesting this assay.

Specimen requirements

Serum - 1ml


Price on application

Laboratory turnaround time

31 days

Laboratory method


Reference range/units

Reported as Normal or a percentage of normal.

Normal is equal or >80% of the control.

Associated tests

Not applicable

Shipping and storage

Sample needs to reach the Laboratory within 8 hours of venepuncture.

Patients with any form of meningococcal disease, particularly if recurrent, should be screened in convalescence with a CH100.

Further information and contact details

For further information, email