Labcode 9A - HIV neutralization Protocol manual Plaque Reduction Assay with GHOST cells

This document contains a detailed protocol of the plaque reduction assays using human cell lines engineered to express CD4 and co-receptors for HIV and SIV entry. 1. The HIV-infected U87.CD4-CCR5 or –CXCR4 cells form syncytia, that is, plaques that can be stained with hematoxylin and enumerated by light microscopy. 2. GHOST(3) cells that have been engineered to express the green fluorescent protein following virus infection. Infected cells show green fluorescence and can be enumerated by fluorescence microscopy. Neutralization is determined by the ability of a serum to reduce the number of plaque forming units (PFU) relative to controls exposed to medium or negative serum. Both assays are run in microtiter format and neutralization is evaluated by manual reading after 3 days.