Fasting preferred but not required

Red serum vial/tube, 5 mL

Immediately after specimen collection, place the tube on wet ice.

1. Allow sample to clot on wet ice
2. Spin at 4^◦ C in a refrigerated centrifuge within two (2) hours of sample collection 
3. Transfer serum to a Screw cap transfer vial/tube (Mayo T465), labelled as serum
4. Freeze within 30 minutes of centrifugation

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

Screw cap transfer vial/tube (Mayo T914)

Frozen - 21 days

Gross lipemia

Automated Liposome Lysis Assay

25-47 U/mL

• Low levels of complement may be due to inherited deficiencies, acquired deficiencies, or due to complement consumption (eg, as a consequence of infectious or autoimmune processes).
• Absent (or low) C2 levels in the presence of normal C3 and C4 values are consistent with a C2 deficiency.
• Low C2 levels in the presence of low C3 and C4 values are consistent with a complement-consumptive process.
• Low C2 and C4 values, in the presence of normal values for C3 is suggestive of C1 esterase inhibitor deficiency.