Rapid detection of avian influenza virus in chicken fecal samples by immunomagnetic capture reverse transcriptase-polymerase chain reaction assay.

Avian influenza virus (AIV) causes great economic losses for the poultry industry worldwide and threatens the human population with a pandemic. The conventional detection method for AIV involves sample preparation of viral RNA extraction and purification from raw sample such as bird droppings. In this study, magnetic beads were applied for immunoseparation and purification of AIV from spiked chicken fecal sample. The beads were conjugated with monoclonal antibodies against the AIV nucleoprotein, which is conserved in all the AIV. The bead-captured virus was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) without RNA extraction because of effective removal of RT-PCR inhibitors. The developed bead-based assay showed a similar detection limit comparable to the RNA extraction and the classic virus isolation method. Using ready-to-use antibody-conjugated bead, the method requires less than 5 h. Furthermore, the method has potential to integrate into a Lab-on-a-chip system for rapid detection and identification of AIV.