Viral identification
For the identification of PIV l, PIV 2, PIV 3, RSV and ADV , samples
were observed under Olympus BX43 LED fluorescence microscope after
direct immunofluorescence staining. Samples were considered qualified
only when the number of epithelial cells was more than 20, which was
judged by at least 2 epithelial cells in each random field at 200×
magnification. When more than 2 green fluorescent cells were found in
visual field, the samples were judged to be positive. When samples were
tested for Flu A and F1u B by colloidal gold method, the quality control
line should appear regardless of whether a test line appears, and the
result was judged to be positive if the test line appeared.