Ordering Guidance

The total complement assay (COM / Complement, Total, Serum) 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.

To evaluate for complement C2, C3, and C4 in one orderable, consider ordering C2 / C2 Complement, Functional, with Reflex, Serum.

Specimen Required

Patient Preparation: Fasting preferred

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice and allow specimen to clot.

2. Centrifuge at 4° C and aliquot serum into a plastic vial.

3. Within 30 minutes of centrifugation, freeze specimen. Sample must be placed on dry ice if not frozen immediately.

NOTE: If a refrigerated centrifuge is not available, it is acceptable to use a room temperature centrifuge, provided the specimen is kept on ice before centrifugation, and immediately afterward, the serum aliquoted and frozen.