High throughput quantitative colorimetric microneutralization assay for the confirmation and differentiation of West Nile Virus and St. Louis encephalitis virus.

Abstract

An automated colorimetric micro-neutralization assay (CmNt) was developed for confirmation and differentiation of West Nile Virus (WNV)-positive human sera as a higher throughput alternative to the standard six-well plaque-reduction neutralization test (PRNT). CmNt was performed in high-capacity 96-well micro-titer plates and required 4-6 days to complete. Inhibition of infection was determined by reduced neutral red-dye retention and conveniently recorded by a colorimetric plate reader. Human sera previously confirmed by PRNT as either negative (N = 52), WNV positive (N = 81), or St. Louis encephalitis virus positive (N = 12) were tested by CmNt; interpreted results were virtually identical to PRNT with a reduced turnaround time and higher throughput. Additionally, a handful of dengue virus positive and negative specimens (four each) were tested by CmNt; interpreted results were identical to PRNT.

• Authors: Michael Taketa-Graham, Jaime L Powell Pereira, Elizabeth Baylis, Cynthia Cossen, Leopoldo Oceguera, Peter Patiris, Robert Chiles, Carl V Hanson, Bagher Forghani, BagHer Forghani
• Journal: The American journal of tropical medicine and hygiene (Am J Trop Med Hyg) Vol. 82 Issue 3 Pg. 501-4 (Mar 2010) ISSN: 1476-1645 [Electronic] United States
• PMID: 20207881 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Topics

• Animals
• Chlorocebus aethiops
• Colorimetry (methods)
• Encephalitis Virus, St. Louis (isolation & purification)
• Neutralization Tests (methods)
• Vero Cells
• West Nile virus (isolation & purification)