Table 1.
Primers used for in vitro transcription of virus RNA standards.
Figure 1.
Schematic showing location of RT-LAMP primer binding sites within HA and NA genes.
(A) HA RT-LAMP primer binding sites. Assay spans region from nucleotide 309–504 with reference to the HA gene sequence of the H7N9 virus strain A/Nanjing/1/2013 (H7N9). (B) NA RT-LAMP primer binding sites. Assay spans region from nucleotide 1097–1295 with reference to the NA gene sequence of the H7N9 virus strain A/Nanjing/1/2013 (H7N9).
Table 2.
Details of primers used for RT-LAMP assay.
Figure 2.
Comparison of real-time turbidity measurement and LFD for the detection of RT-LAMP products.
HA (A and C) and NA (B and D) RT-LAMP on 10-fold serial dilutions of H7N9 virus RNA. (A and B) detection using the real-time turbidimetry device. DW: distilled water used as non-RNA negative control. (C and D) detection using LFD. Loop primers were tagged with Biotin and FITC.
Figure 3.
Specificity test results of RT-LAMP-LFD for H7N9 virus detection.
The specificities of HA (A) and NA (B) RT-LAMP-LFD assays were determined by analyzing the RNA extracts from various control viruses and the reference virus. N: No template control; 1: human seasonal influenza A H1N1 virus; 2: human seasonal influenza A H3N2 virus; 3: human influenza B virus; 4: 2009 swine-origin influenza virus A H1N1 virus; 5: avian influenza A H5N1 virus; 6: avian influenza A H9N1 virus; 7: parainfluenza virus types 1; 8: parainfluenza virus types 2; 9: parainfluenza virus types 3; 10: parainfluenza virus types 4; 11: human coronavirus 229E; 12: human coronavirus OC43; 13: human coronavirus HKU1; 14: human coronavirus NL63; 15: respiratory syncytial viruses types A; 16: respiratory syncytial viruses types B; 17: H7N9 virus.
Table 3.
Performance of RT-LAMP-LFD assay compared with the reference standard for detecting avian-origin influenza A (H7N9) virus.