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

More general terms

• nontreponemal serologic test for syphilis

Additional terms

• syphilis