Labcode 4A and 4B- HIV neutralization testing with Monogram Biosciences, USA

This document contains a detailed protocol of a recombinant virus assay, developed to measure virus-antibody neutralization during a single round of virus replication. HIV genomic RNA is isolated from virus stocks or plasma, Env sequences amplified by PCR and ligated to an expression vector and, subsequently, to a HIV genomic vector carrying the luciferase reporter gene. Polyclonal or monoclonal antibodies were used for neutralisation on U87 cells expressing CD4 plus the CCR5 and CXCR4 co-receptors. Virus infectivity was determined 72 h post-inoculation by measuring the amount of luciferase activity expressed in infected cells.