what is t pallidum ab (fta-ab)
Fluorescent treponemal antibody absorption test The antigen for the FTA-ABS test is whole bacteria. The bacteria cannot be cultured on laboratory media, so the organisms used are a lyophilized suspension of T. pallidum extracted from rabbit testicular tissue. This is spread over and fixed to a slide. Patient serum is mixed with an absorbent (the "ABS" part of the test) containing an extract of a non-pathogenic treponeme, Treponema phagedenis biotype Rieter. The purpose of the absorbent is to remove anti-treponemal antibodies that are not specific for the syphilis bacteria. The pre-adsorbed patient serum is then added to the slide; if the patient has been infected by syphilis, their antibodies will bind to the bacteria. FITC (a fluorophore)-labeled anti-treponeme antibody and TRITC (another fluorophore)-labeled anti-human antibodies are added as secondary antibodies. The spirochete location is identified using the FITC staining and the TRITC staining identifies whether the patient has anti-T. pallidum antibodies (binding to the same spirochete).
Bir Tawil Bir Tawil or Bi'r Tawīl (Egyptian Arabic: بير طويل‎ Bīr Ṭawīl  [biːɾ tˤɑˈwiːl] or بئر طويل Bi’r Ṭawīl, meaning "tall water well") is a 2,060 km2 (800 sq mi) area along the border between Egypt and Sudan, which is uninhabited and claimed by neither country. When spoken of in association with the neighbouring Hala'ib Triangle, it is sometimes referred to as the Bir Tawil Triangle, despite the area's quadrilateral shape; the two "triangles" border at a quadripoint.