Specimen Requirements

Container/Tube:

Preferred: Gold-top serum gel tube or plain, red-top tube

Acceptable: Green-top (lithium heparin) tube or lavender-top (EDTA) tube 

Specimen Volume: 165 uL of serum or plasma

Stability: Store samples at 2 to 8°C if not tested within 8 hours of collection.  Store samples stoppered and upright at all times at 2 to 8°C up to 2 days. Freeze samples, devoid of red blood cells, at or below -20°C for up to 180 days.  Thoroughly mix thawed samples and centrifuge at 10,000 g for 2 minutes before using.

Collection Instructions:

1. Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference and anomalous values may be observed. Additional information may be required for diagnosis.

2. Heparin has been shown to increase the index values in some HBc IgM reactive samples by up to 28% relative to serum. Results falling near the cutoff should be interpreted with caution.

3.  This assay is affected by biotin interference.