Highly sensitive SIV plasma viral load assay: practical considerations, realistic performance expectations, and application to reverse engineering of vaccines for AIDS

J Med Primatol. 2005 Oct;34(5-6):303-12. doi: 10.1111/j.1600-0684.2005.00128.x.


As new assay methods for quantitative reverse transcription-polymerase chain reaction (RT-PCR), such as real time RT-PCR techniques, approach theoretical limits of per reaction sensitivity, further increments in the sensitivity of measurements of viral load can only be achieved by increasing the amount of input RNA per reaction. We describe a robust, convenient, rapid integrated approach for specimen preparation and real time RT-PCR assay for plasma simian immunodeficiency virus (SIV) RNA viral load that provides a threshold sensitivity of 10 copy Eq/ml, and tolerates less than optimally processed specimens. The method provides accurate quantitation of viral load for the SIV virus isolates in common use for non-human primate studies. We demonstrate the utility of the method in sensitively tracking viral load in an animal showing effective control of viral replication to levels below the threshold for quantitation in conventional assays.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS Vaccines / genetics*
  • Animals
  • DNA Primers
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Reverse Transcriptase Polymerase Chain Reaction / veterinary*
  • Sensitivity and Specificity
  • Simian Immunodeficiency Virus / genetics*
  • Specimen Handling / methods
  • Specimen Handling / veterinary
  • Viral Load / methods*
  • Viral Load / veterinary*


  • AIDS Vaccines
  • DNA Primers