|Kwarta, Karen - IOWA STATE UNIVERSITY|
|Driskell, Jeremy - IOWA STATE UNIVERSITY|
|Porter, Marc - IOWA STATE UNIVERSITY|
Submitted to: Proceedings of the Office International Des Epizooties World Association of
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2005
Publication Date: October 3, 2005
Citation: Kwarta, K., Driskell, J., Neill, J.D., Ridpath, J.F., Porter, M. 2005. Detection of viral pathogens in an immunoassay format with atomic force microscopy as a readout method [abstract]. New Diagnostic Technology: Applications in Animal Health & Biologics Controls International Congress. Office International Des Epizooties. p. 81. Technical Abstract: We have developed a sensitive, rapid, and direct readout method for virus detection method that couples the binding specificity of antibody-antigen interactions with the ultrahigh resolution imaging capabilities of atomic force microscopy (AFM). The designed platform can be applied to the simultaneous readout of many different viral pathogens by taking advantage of the ability of AFM to identify nanometer-sized objects based on size and shape, thus distinguishing viruses based upon morphology. This capability is demonstrated by the detection of feline calicivirus (FCV) captured directly from cell culture lysates by covalently immobilized monoclonal antibodies (mAbs) and quantified by AFM. Dose response curves, established by exposure of virus serum to the capture platform for ~12 h at 25 C, are linear with a detection limit of 3 x 10**6 FCV viruses/mL. In an effort to reduce the overall analysis time, binding kinetics for FCV were examined at two different temperatures (25 C and 37 C). Results show that the exposure time can be reduced to 1 h at 37 C while maintaining a limit of detection of 6 x 10**6 viruses/mL. This method was also used as an antibody screening tool to identify the most effective mAbs for FCV as well as for parvovirus. Preliminary findings from attempts at dual-analyte detection of FCV and parvovirus will also be briefly discussed.