Enhancement of immunohistochemical detection of HIV-1 p24 antigen in brain by tyramide signal amplification

J Virol Methods. 1997 Aug;67(1):103-12. doi: 10.1016/s0166-0934(97)00083-9.


Human immunodeficiency virus type 1 (HIV-1) infection of the brain has been demonstrated in formalin fixed, paraffin embedded post-mortem brain tissue (PM) by chromogenic immunohistochemistry for the HIV p24 antigen. The sensitivity of antigen detection is increased significantly by tyramide signal amplification (TSA) compared to the conventional peroxidase labelled Avidin-Biotin complex (ABC) technique. The TSA method also permitted the use of a lower concentration of primary antibody than is conventionally used. Sensitivity was enhanced further by microwave irradiation of the paraffin embedded tissues in citrate buffer. HIV-1 p24 antigen was also detected in PM brain tissue by TSA enhanced immunofluorescence and demonstrated increased sensitivity compared to the conventional immunofluorescence technique with a greatly reduced autofluorescence background.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain / virology*
  • Fluorescent Antibody Technique
  • HIV Antibodies
  • HIV Core Protein p24 / analysis*
  • HIV Infections / virology
  • HIV-1 / isolation & purification*
  • Humans
  • Immunoenzyme Techniques*
  • Microwaves
  • Paraffin Embedding
  • Sensitivity and Specificity
  • Tyramine / analogs & derivatives*


  • HIV Antibodies
  • HIV Core Protein p24
  • Tyramine