rna seq of covid-19 patients: white blood cells
Blood samples from COVID-19 patients or healthy individuals were treated with red blood cell lysis buffer to isolate whole white blood cells. These were lysed in RLT buffer and used for total RNA purification with the RNeasy Micro kit (Qiagen). RNA samples were treated with DNase I (Qiagen) and used for the preparation of NGS libraries with the TruSeq RNA Library Prep Kit v2 (Illumina). Libraries were quantified using a Qubit dsDNA HS Assay Kit (Thermo Scientific), and quality of the libraries was validated on an Agilent 2100 Bioanalyzer. Bar-coded cDNA libraries were pooled together in equal concentrations and sequenced on a NextSeq 500 System (Illumina) at the Greek Genome Center (Biomedical Research Foundation, Academy of Athens, Athens, Greece).