Figure 1.
Visual detection of amplified LAMP products using SYBR green I.
Addition of 1 µl of diluted SYBR green I to the reaction tube after LAMP reaction enables visible analysis of the results under natural light (Figure 1A) or UV irradiation (Figure 1B). The color changes from orange (negative reaction) to green (positive reaction) (Figure 1A) and bright fluorescence indicates a positive reaction (Figure 1B).
Figure 2.
Sensitivities of the RT-LAMP and direct RT-LAMP assays for the detection of human EV71.
The assay was carried out using different concentrations of RNA from a titrated EV 71 subgenotype C4 isolate (Strain FY17.08/AN/CHN/2008, GenBank accession no. EU703812) and monitored by real-time measurement of turbidity. The detection limits of the RT-LAMP (Figure 2A) and direct RT-LAMP (Figure 2B) assay for EV71 were 0.1 and 1.6 TCID50 per reaction, respectively.
Table 1.
Comparison of results of direct RT-LAMP assay with RT-LAMP assays obtained from 145 clinical nasopharyngeal swab specimens.
Table 2.
Comparison of results of direct RT-LAMP assay with qRT-PCR assays obtained from 145 clinical nasopharyngeal swab specimens.
Table 3.
Preliminary study of sample treatment for EV71 detection by direct RT-LAMP using various lysis buffers and heat-treatment.