Fig. 3

Comparative sensitivity of real-time RT-LAMP, one-step RT-PCR, and real-time RT-PCR methods. Real-time RT-LAMP, one-step RT-PCR and real-time RT-PCR were performed using viral RNAs at the concentrations ranging from 10^4.0 to 10⁻² TCID₅₀/mL per tube. a and b Detection limit of real-time RT-LAMP. LAMP products were detected using a real-time turbidity assay with an LA-320c (a) and a fluorescence assay (b). c Detection limit for the one-step RT-PCR using the same RNA extracts that were used for real-time RT-LAMP. PCR products were observed in a 1.5 % agarose gel that was stained with ethidium bromide. The lanes from left to right were as follows: lane M, DNA marker DL2000; lanes 1 ~ 7, the one-step RT-PCR results from10^4.0 to 10⁻² TCID₅₀/mL diluted virions; lanes 8, negative control. d Detection limit for real-time RT-PCR using the same RNA extracts that were used for real-time RT-LAMP. PCR products were detected using a real-time fluorescence assay with an ABI7500 system. Line 1–7, the real-time RT-PCR results from10^4.0 to 10⁻² TCID₅₀/mL diluted virions; Line8, negative control