NewBio TPHA is a passive particle agglutination assay for the qualitative detection of IgG and IgM antibodies to Treponema pallidum in human serum, EDTA plasma, or CSF and to determine the titre level of the samples.
NewBio TPHA uses preserved avian erythrocytes coated with extracted antigens of T.pallidum (Nichols strain). Specific antibodies present in a sample of plasma or serum bind to these antigens when the sample is incubated with the particles. This causes the particles to agglutinate, then settle to form a characteristic pattern in the test well.
Non-specific reactions are eliminated by the use of absorbents. The assay is run and interpreted manually.
Description
Haemagglutination assay for syphilis
Native antigen and avian erythrocytes
All reagents ready to use.
TPHA Test cells TPHA Control cells TPHA Diluent TPHA Negative control TPHA Positive control
Simple protocol: 1 x 45 minute incubation
Manual
Only requires 10 µL sample
Serum, EDTA Plasma, CSF
Specificity
A study with 1248 syphilis negative EDTA plasma samples showed 99.92% specificity (95% confidence interval 99.55-100.0%).
Sensitivity
A study with 205 syphilis positive samples (48 EDTA plasma and 157 sera) showed 100% sensitivity (95% confidence interval 98.22-100.0%).
Limit of detection
NewBio TPHA has an expected limit of detection of ≤0.1 IU/mL against the WHO 1st IS for human syphilitic plasma IgG NIBSC code: 05/122.
