SYPHILIS ELISA KIT
INTENDED USE
This Syphilis ELISA Kit is to be used for the in vitro detection of IgG/IgM type antibodies to Treponema pallidum in human serum or plasma. This Syphilis ELISA Kit is intended for LABORATORY RESEARCH USE only, and is not for use in diagnostic or therapeutic procedures.
INTRODUCTION
Syphilis is a complex sexually transmitted disease that is caused by the spirochaete T. pallidum. The disease evolves through primary, secondary and latent stages. Tertiary manifestations of syphilis may occur from one to thirty years after primary infection and include the development of gummatous lesions, cardiovascular syphilis and neurological syphilis. T. pallidum cannot be cultured in vitro and therefore diagnosis is dependent on clinical signs, direct observation of the bacteria from lesions, and serology. Except for very early disease, serological procedures are the preferred diagnostic method for syphilis at all stages. Two types of serological tests are used: non-treponemal and treponemal. Both non-treponemal and treponemal serology as well as clinical history is required for definitive diagnosis.
Non-treponemal tests detect antibodies reactive with a lipoidal antigen consisting of cardiolipin, lecithin and cholesterol. These non-treponemal antibodies are thought to be generated in response to lipid associated with the treponeme cell surface. The non-treponemal tests may be used for screening and to monitor the effectiveness of therapy. Treponemal tests detect antibodies reactive with whole T. pallidum or sonicates thereof. Typically, sera must be adsorbed with an extract of non-pathogenic treponemes to remove cross-reactive antibodies prior to performing treponemal tests. Treponemal tests become reactive after primary infection and in most cases remain positive for the lifetime of the patient. Test sensitivity varies with the stage of syphilis (primary 69-100%, secondary 100%, latent 97-100%, and late 94-96%). False negative results are associated with early primary disease and prozone reactions can occur in the agglutination-based treponemal tests. Treponemal tests have a specificity of 94-100% in normal populations.
The T. pallidum antigen has been identified as an abundant, immunodominant and putatively pathogen-specific membrane lipoprotein of T. pallidum. Antibodies to the T. pallidum antigen protein have been identified in patients with syphilis and in infants with congenital syphilis by immunoblot and by enzyme immunoassay.
PRINCIPLE OF THE ASSAY
Syphilis ELISA Kit
Syphilis ELISA Kit is to be used for the in vitro detection of IgG/IgM type antibodies to Treponema pallidum in human serum or plasma. This Syphilis ELISA Kit is intended for LABORATORY RESEARCH USE only, and is not for use in diagnostic or therapeutic procedures. This Syphilis ELISA Kit employs a technique called a qualitative sandwich immunoassay.
The microtiter plate provided in this Syphilis ELISA Kit has been pre-coated with highly purified specific T. pallidum antigen. Samples or controls are added to the microtiter plate wells and incubated. T. pallidum IgG/IgM specific antibodies if present, will bind to and become immobilized by the antigen pre-coated on the wells. The microtiter plate wells are thoroughly washed to remove unbound other components of the sample. A standardized preparation of horseradish peroxidase (HRP) conjugated goat anti-human IgG/IgM antibodies is added to each well to “sandwich” the antibodies immobilized during the first incubation. The microtiter plate then undergoes a second incubation. The wells are thoroughly washed to remove all unbound HRP conjugate and a TMB (3,3',5,5' Tetramethyl-benzidene) substrate solution is added to each well. The enzyme (HRP) and substrate are allowed to react over a short incubation period. Only those wells that contain T. pallidum IgG/IgM specific antibodies and HRP conjugate will exhibit a change in colour. This enzyme substrate reaction is terminated by the addition of sulphuric acid solution and the colour change is measured spectrophotometrically at a wavelength of 450 nm. Samples with O.D values greater than or equal to the Cut-off Value are considered reactive by the criteria of this Syphilis ELISA Kit.
Download Product Data Sheet