Diphtheria immunity/vaccination studies

SDRU offers a referred (charged for) service for the determination of serum antibodies to diphtheria toxin. Diphtheria immunity status is determined by a tissue culture toxin neutralisation assay of serum antibodies specific for diphtheria toxin. Test plates are incubated for up to six days before a final report is issued. This assay can be more reliable than ELISA, particularly for detecting susceptible individuals. Results are reported in International Units/ml and classified as:

• Individual is susceptible: <0.016 IU/ml;
• Levels conferring some protection: 0.016 - 0.09 IU/ml;
• Protective levels: 0.1 - 0.9IU/ml;
• Levels conferring long-term protection: >1.0IU/ml.

Turnround time: Tests are batched every three weeks, unless a sample is deemed urgent. The turnaround time is 21 days.

How to obtain service

Use the R3 Streptococcus & diphtheria referral form (PDF, 349 KB)and supply not less than 200 µl of serum.

Please supply details of vaccination history (if known) with all requests plus relevant clinical details. Specimen submissions regarded by the sending laboratory as urgent should be notified to SDRU by telephone (020 8327 7270/7289) to ensure that the appropriate level of priority is accorded to these specimens immediately upon receipt.