Development of rapid immunochromatographic strip test for the detection of porcine epidemic diarrhoea virus

Lyoo, Kwang-Soo; Yeom, Minjoo; Kim, Jungho; Kim, Donghyuk; Ha, Gunwoo; Na, Woonsung; Le, Van Phan; Song, Daesub

Cells infected with PEDV and stained with mAb 3B12-1A6 or mAb 1H12-1C6 showed typical cytoplasmic fluorescence of PEDV on the IFA, while the other cells infected with TGEV, PRCV and porcine rotavirus did not show fluorescence for both PEDV mAbs (Fig 1b) . The best result for detecting the PEDV detection threshold was obtained using the optimised concentration of the monoclonal antibodies in the ICA kit. We applied 0.60±0.12 µg mAb anti-PED 3B12-1A6 to a nitrocellulose membrane. The maximum intensity of test line colouring was detected when the mAb anti-PED 1H12-1C6 conjugated with 0.1±0.02 µg colloidal gold of coated on a glass fibre membrane for immobilisation. Further increasing the mAb concentration did not increase test line intensity. Positive results for PEDV-DR13, PEDV-KNU1309, PEDV-KNU1303 and PEDV-KNU1402 strains were demonstrated by the visualisation of two red-purple bands at the test line and control line on the ICA kit. However, TGEV, PRCV and porcine rotavirus were considered negative when only one band appeared in the control line, such as the cell culture medium. In the determination of the sensitivity of the ICA kit, real-time RT-PCR showed a sensitivity of up to 10 2.0 TCID 50 /ml of PEDV, while the detection limit of the ICA kit was 10 4.0 TCID 50 /ml (Table 2) .