mNGS:respiratroy tract
For RNA procedure, Maxwell RSC simply RNA Tissue Kit (Promega, USA) was used for RNA extraction. Reverse transcription and second strand synthesis were performed using NEBNext Ultra II RNA First Strand Synthesis Module and Non-Directional RNA Second Strand Synthesis Module. In these steps, the incubation under 65 for 5 minutes was replaced by fragmentation at 94. After DNA purification with Ampure XP beads, library preparation was performed with TruePrep DNA Library Prep Kit V2 for Illumina.