Syphilis is a sexually transmitted (venereal) disease caused by the spirochete Treponema pallidum. The disease can also betransmitted congenitally thereby attaining its importance in antenatal screening. After infection the host forms non-treponemalanti lipoidal antibodies (reagins) to the lipoidal material released from the damaged host cells as well as Treponema specificantibodies. Serological tests for non-treponemal antibodies such as VDRL, RPR, TRUST etc. are useful as screening tests.Tests for Treponema specific antibodies such as TPHA, FTA-ABS, rapid Treponema antibody tests are gaining importance asscreening as well as confirmatory tests because they detect the presence of antibodies specific to Treponema pallidum.
Syphicheck WB is a modified TPHA, which qualitatively detects the presence of IgM and IgG class of Treponema specificantibodies during syphilis in whole blood, serum or plasma specimens within 15 minutes.
Principle
Syphicheck WB utilizes the principle of agglutination of antibodies/ antisera with respective antigen in immuno-chromatography format along with use of nano gold particles as agglutination revealing agent. As the test sample flowsthrough the membrane assembly of the test device , the recombinant Treponema pallidum antigens (47 kDa, 17 kDa) -colloidal gold conjugate forms a complex with Treponema specific antibodies in the sample. This complex moves further onthe membrane to the test region where it is immobilized by the recombinant Treponema pallidum antigens (47 kDa, 17 kDa)coated on the membrane leading to the formation of a pink to deep purple coloured band at the test region 'T’ which confirms apositive test result. Absence of this coloured band in test region ‘T’ indicates a negative test result. The unreacted conjugateand the unbound complex if any, along with rabbit globulin - colloidal gold conjugate move further on the membrane and aresubsequently immobilized by the Agglutinating sera for rabbit globulin coated on the membrane at the control region, forming apink/purple coloured band. This control band serves to validate the test results.
