FIG. 3.

SNAP probing ELISA. RT-PCR amplification was performed using the optimized protocol on the IRES region with FITC-labeled IRES2 primer and unlabeled IRES4 primer. The SNAP capture probe was IRES3-biotin. As a control, capture probe P2-biotin was used. RNA samples were derived from cells infected with all seven FMDV serotypes (O, A, C, Asia 1, SAT 1, SAT 2, and SAT 3) and various negative controls (uninfected cells, SVD virus-infected cells, and ddH₂O) were also included. Two samples from each isolate were analyzed using 1 or 5 μl of the cDNA reaction mixtures from total RNA isolated from cell cultures. The RT-PCR products of the 1-μl samples were also electrophoresed into agarose gels and stained with ethidium bromide. Lanes: M, size marker; 1 to 7, the seven serotypes of FMDV; 8, negative cell culture; 9, SVD virus in cell culture; 10, ddH₂O negative control. The products are around 250 bp.