Syphilis (Click Here for Product List)
Syphilis is a chronic venereal infection caused by the spirochaete micro-organism Treponema pallidum. The disease is an enormous problem for clinicians and blood bankers world-wide. Although in the main a sexually transmitted disease, the transfusion of infected blood will pass this unpleasant illness to the unwitting recipient of pathogenetically compromised plasma.
As the organism cannot be cultured on artificial media, diagnosis of syphilis depends on the detection of specific antibodies by serological tests in combination with clinical findings.
VDRL Carbon Antigen
The VDRL test is “non-treponemal” in that the antibodies detected are not specific for T. pallidum, although their presence in patient’s serum or plasma is strongly associated with infection by the organism. This test measures antibody (IgG and IgM) produced in response to lipoidal material released from damaged host cells as well as to lipoprotein-like material released from the spirochaetes. These antibodies tend to disappear after successful treatment of the infection.
The reagent consists of cardiolipin lecithin, which will flocculate when exposed to patient serum containing reagin found in syphilitic patients. VDRL carbon antigen is extremely useful in epidemiological studies.
RPR
The Rapid Plasma Reagin kit contains VDRL Carbon Antigen as described above. This macroscopic “non-treponemal” flocullation test, is also used to detect and quantify reagin antibodies, thus providing a presumptive test for Syphilis.
TPHA
Biotec TPHA is a Syphilis confirmatory test using preserved avian erythrocytes coated with antigens of T. Pallidum, which will bind with specific antibody present in patient’s serum or plasma. The cells are suspended in a medium containing components to eliminate non-specific reactions. Positive reactions are shown by agglutination of the cells, negative reactions by the settling of the cells to a button or small ring.
Although the kit is intended for use primarily as a qualitative test, antibody levels may be titrated by doubling dilution. Agglutination patterns may be interpreted by eye or by a plate-reader capable of reading agglutination patterns.
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