Optimization and validation of the TZM-bl assay for standardized assessments of neutralizing antibodies against HIV-1

J Immunol Methods. 2014 Jul;409:131-46. doi: 10.1016/j.jim.2013.11.022. Epub 2013 Dec 1.


The TZM-bl assay measures antibody-mediated neutralization of HIV-1 as a function of reductions in HIV-1 Tat-regulated firefly luciferase (Luc) reporter gene expression after a single round of infection with Env-pseudotyped viruses. This assay has become the main endpoint neutralization assay used for the assessment of pre-clinical and clinical trial samples by a growing number of laboratories worldwide. Here we present the results of the formal optimization and validation of the TZM-bl assay, performed in compliance with Good Clinical Laboratory Practice (GCLP) guidelines. The assay was evaluated for specificity, accuracy, precision, limits of detection and quantitation, linearity, range and robustness. The validated manual TZM-bl assay was also adapted, optimized and qualified to an automated 384-well format.

Keywords: Assay validation; GCLP; HIV; Neutralizing antibody; TZM-bl cells.

Publication types

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

MeSH terms

  • Antibodies, Neutralizing / blood*
  • Automation, Laboratory / standards
  • Biomarkers / blood
  • Guideline Adherence / standards
  • HIV Antibodies / blood*
  • HIV Infections / blood
  • HIV Infections / diagnosis*
  • HIV Infections / immunology
  • HIV-1 / genetics
  • HIV-1 / immunology*
  • HeLa Cells
  • High-Throughput Screening Assays / standards*
  • Humans
  • Limit of Detection
  • Neutralization Tests / standards*
  • Observer Variation
  • Practice Guidelines as Topic / standards
  • Predictive Value of Tests
  • Quality Control
  • Reproducibility of Results
  • Time Factors
  • Transfection


  • Antibodies, Neutralizing
  • Biomarkers
  • HIV Antibodies