Buffy coat transcriptomic analysis in severe COVID-19 patients
From total RNA, 1 ug was used to prepare the small RNA libraries with the TruSeq Small RNA Library Prep Kit (Illumina, USA). The protocol was followed as described by the manufacturer, with the exception of the cDNA construction purification step, which was carried out using 3% Agarose Gel Cassette for targets between 100 bp - 250 bp in a BluePippin system (Sage Science, USA). Libraries were quantified by qPCR using a KAPA Library Quantification Kits for Illumina platforms (KAPA Biosystems, USA). Sequencing was performed on a NextSeq 500 System (Illumina). It was used a NextSeq 500/550 High Output v2 kit (75 cycles) and 1x50 bp single-end reads were obtained.