title: A rapid assay for Hendra virus IgG antibody detection and its titre estimation using magnetic nanoparticles and phycoerythrin.
abstract: Detection of Hendra viral IgG antibody in animal sera is useful for surveillance following a virus outbreak. The commonly used enzyme-linked immunosorbent assay and fluorescence-based Luminex assay typically consist of three steps and take at least several hours to complete. We have simplified the procedure to two steps in an effort to develop a rapid procedure for IgG antibody, but not IgM antibody, detection. This is achieved by conjugating the fluorescence label R-phycoerythrin directly onto the IgG binding protein Protein G. The use of magnetic nanoparticles, due to their large specific surface area, has helped reduce each of the binding steps to 20 min. As a result, the whole assay can be completed in 60 min. We also demonstrate a method to quickly estimate IgG antibody titres by assaying the sera at only two dilutions (i.e. 1:20 and 1:1000) and using the fluorescence ratio at these dilutions as an indicator of antibody titre. The results of this approach correlated well with the well-regarded serum neutralization test in virus antibody assays. This protocol reported here can be adopted in Luminex assays, fluorescence-linked immunosorbent assays and assays on microfluidics platforms for rapid antibody surveillance of Hendra and other viruses.
authors.affiliation: CSIRO Manufacturing Flagship, Bayview Ave, Clayton, VIC 3168, Australia. Electronic address: yuan.gao@csiro.au.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: CSIRO Biosecurity Flagship, East Geelong, VIC 3219, Australia.
authors.forename: Jackie
authors.initials: J
authors.lastname: Pallister
authors.affiliation: CSIRO Manufacturing Flagship, Bayview Ave, Clayton, VIC 3168, Australia.
authors.forename: Florian
authors.initials: F
authors.lastname: Lapierre
authors.affiliation: CSIRO Biosecurity Flagship, East Geelong, VIC 3219, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Crameri
authors.affiliation: CSIRO Biosecurity Flagship, East Geelong, VIC 3219, Australia.
authors.forename: Lin-Fa
authors.initials: LF
authors.lastname: Wang
authors.affiliation: CSIRO Manufacturing Flagship, Bayview Ave, Clayton, VIC 3168, Australia; Melbourne Centre for Nanofabrication, 151 Wellington Road, Clayton, VIC 3169, Australia. Electronic address: yonggang.zhu@csiro.au.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001426:Bacterial Proteins / Q000378:metabolism*; D005470:Fluorometry / Q000379:methods; D045404:Hendra Virus / Q000276:immunology*; D045464:Henipavirus Infections / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D007074:Immunoglobulin G / Q000097:blood*; D008280:Magnetics; D053758:Nanoparticles / Q000378:metabolism; D010799:Phycoerythrin / Q000032:analysis*; D013194:Staining and Labeling; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral; D001426:Bacterial Proteins; C034284:IgG Fc-binding protein, Streptococcus; D007074:Immunoglobulin G; D010799:Phycoerythrin
keywords: Antibody; Hendra virus; Immunoassay; Magnetic nanoparticles; Phycoerythrin