Specific detection of foot-and-mouth disease serotype Asia 1 virus by carboxyl-magnetic beads conjugated with single-domain antibody

Abstract

Background: Immunomagnetic nanobead (IMNB) labeled with specific antibody, has been demonstrated to be useful for the capturing and detection of viruses. Results: In this study, we developed an imunomagnetic bead based on carboxyl-magnetic beads (MNB) labeled with a single-domain antibody (sdAb) for capturing foot-and-mouth disease (FMD) Asia 1 virus. After magnetic separation, complexes of MNB-sdAb-virus were detected with either a sandwich ELISA or QDs-C5 probe under a fluorescence microscope, and the complexes were used as templates for extraction of total RNA for amplification of the VP1 or 3D gene fragments using RT-PCR and real-time RT-PCR. The Asia 1 VLPs were efficiently captured through IMNB with a high binding rate of 5.09μg of antigen/μl of bead suspension. Moreover, this method has been successfully used to capture Asia 1 antigen in synthetic samples. Conclusion: Ultimately, a specific and highly sensitive capture FMDV Asia 1 tool has been established that has the potential to enhance the sensitivity and reliability when diagnosing FMDV Asia 1.