Verification of the PRRSV RT-LAMP assay. RT-LAMP was used to amplify a positive control template and compared to a negative control. The output of the RT-LAMP assay was monitored by gel electrophoresis and color change. (A) 1% agarose gel electrophoresis of the RT-LAMP products. Lanes: M; DL2000 Marker, 1; negative control, 2; positive control. (B) Color change in the RT-LAMP reaction was monitored followig addition of SYBR Green I dye. Tube 1: negative control, Tube 2: positive control. (C) The positive and negative controls were verified by RT-PCR 1% agarose gel electrophoresis of the RT-PCR products. Lanes: M; DL2000 Marker, 1; negative control, 2; positive control.