title: Increased Sensitivity of HIV-1 p24 ELISA Using a Photochemical Signal Amplification System.
abstract: BACKGROUND
  In this study we describe a photochemical signal amplification method (PSAM) for increasing of the sensitivity of enzyme-linked immunosorbent assay (ELISA) for determination of HIV-1 p24 antigen. The photochemical signal amplification method is based on an autocatalytic photochemical reaction of a horseradish peroxidase (HRP) substrate, orthophenylenediamine (OPD).
  
  
  METHODS
  To compare the performance of PSAM-boosted ELISA with a conventional colorimetric ELISA for determination of HIV-1 p24 antigen we employed a PerkinElmer HIV-1 p24 ELISA kit, using conventional ELISA alongside ELISA + PSAM.
  
  
  RESULTS
  In the present study, we show that PSAM technology allows one to increase the analytical sensitivity and dynamic range of a commercial HIV-1 p24 ELISA kit, with and without immune-complex disruption, by a factor of approximately 40-fold.
  
  
  CONCLUSIONS
  ELISA + PSAM is compatible with commercially available microtiter plate readers, requires only an inexpensive illumination device, and the PSAM amplification step takes no longer than 15 min. This method can be used for both commercially available and in-house ELISA tests, and has the advantage of being considerably simpler and less costly than alternative signal amplification methods. This method can be used for both commercially available and in-house ELISA tests, and has the advantage of being considerably simpler and less costly than alternative signal amplification methods.
authors.affiliation: Allied Innovative Systems, Hillsborough, NJ (Santockyte is now with Bristol-Myers Squibb, Princeton, NJ).
authors.forename: Simon
authors.initials: S
authors.lastname: Bystryak
authors.forename: Rasa
authors.initials: R
authors.lastname: Santockyte
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D016655:HIV Core Protein p24 / Q000302:isolation & purification*; D015658:HIV Infections / Q000175:diagnosis; D015497:HIV-1 / Q000302:isolation & purification*; D006735:Horseradish Peroxidase; D006801:Humans; D010655:Phenylenediamines / Q000737:chemistry; D010777:Photochemistry / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D016655:HIV Core Protein p24; D010655:Phenylenediamines; C034193:1,2-diaminobenzene; D006735:Horseradish Peroxidase