toluidine red unheated serum test (TRUST)

Indications: - syphilis Principle: - nontreponemal serologic tests used in the diagnosis of syphilis include: - VDRL reagin slide - rapid plasma reagin circle card (RPR) - unheated serum reagin (USR) - toluidine red unheated serum test (TRUST) - all of these tests are based upon detection of immunoglobulin, IgG or IgM (reagin) directed against non treponemal antigens - all nontreponemal assays utilize an active phospholipid (cardiolipin) antigen combined with lecithin & cholesterol in a colloidal particle Methods: - antigen is mixed with dye in the TRUST to make flocculation of lipids by plasma antibody macroscopically visible

References

Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 1186