Virus detection using filament-coupled antibodies.
Two attractive features of ELISA are the specificity of antibody-antigen recognition and the sensitivity achieved by enzymatic amplification. This report describes the development of a non-enzymatic molecular recognition platform adaptable to point-of-care clinical settings and field detection of biohazardous materials. This filament-antibody recognition assay (FARA) is based on circumferential bands of antibody probes coupled to a 120 microm diameter polyester filament. One advantage of this design is that automated processing is achieved by sequential positioning of filament-coupled probes through a series of 25-60 microL liquid filled microcapillary chambers. This approach was evaluated by testing for the presence of M13KO7 bacterial virus using anti-M13KO7 IgG(1) monoclonal antibody coupled to a filament. Filament motion first positioned the antibodies within a microcapillary tube containing a solution of M13KO7 virus before moving the probes through subsequent chambers, where the filament-coupled probes were washed, exposed to a fluorescently labeled anti-M13K07 antibody, and washed again. Filament fluorescence was then measured using a flatbed microarray scanner. The presence of virus in solution produced a characteristic increase in filament fluorescence only in regions containing coupled antibody probes. Even without the enzymatic amplification of a typical ELISA, the presence of 8.3 x 10(8) virus particles produced a 30-fold increase in fluorescence over an immobilized negative control antibody. In an ELISA comparison study, the filament-based approach had a similar lower limit of sensitivity of approximately 1.7 x 10(7) virus particles. This platform may prove attractive for point-of-care settings, the detection of biohazardous materials, or other applications where sensitive, rapid, and automated molecular recognition is desired.
Stone
Gregory P
GP
Biomedical Engineering, Box 1510 Station B, Vanderbilt University, Nashville, TN 37235, USA.
Mernaugh
Ray
R
Haselton
Frederick R
FR
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000918:Antibody Specificity; D001331:Automation; D001435:Bacteriophages / Q000276:immunology / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D005453:Fluorescence; D007124:Immunoenzyme Techniques / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods; D014780:Viruses / Q000302:isolation & purification*
D000911:Antibodies, Monoclonal