Functional antibody to Neisseria meningitidis serogroup B by Serum Bactericidal Antibody Assay (SBA)
Collection container (including preservatives):
Clotted blood sample tube (no preservative)
Specimen type: Clotted blood/serum, paired
Specimen transport: Ambient temperature via
porter, courier, Royal Mail or DX compliant with IATA packing
Minimum volume of sample: Minimum volume
Special precautions: If processing is delayed,
refrigeration is preferable to storage at ambient temperature.
Delays of over 48hr are undesirable.
Measurement units: SBA Titres expressed as the
reciprocal of the final serum dilution giving ≥ 50% killing at 60
minutes calculated from the number of colony forming units (cfu) in
Biological reference units: Not applicable
Turnaround time: 28 working days
Clinical decision points: For putative
protection against serogroup B, the SBA titre must be ≥ 4 for at
least 2 of the 3 strains used.
Factors known to significantly affect the
results: As this is a 'killing type' assay using live
bacteria, antibiotics can impact on results. A control to monitor
this is included in the assay.
The effect and impact of Eculizumab therapy on this assay is
currently under investigation