AIRR-Seq of Homo sapiens: Blood samples from COVID-19 patients
Total RNA was used to synthesize cDNA, using the Superscript IV First-Strand Synthesis System (Invitrogen), with a primer targeting the immunoglobulin kappa/lambda chain C1 domain according to the manufacturers protocol. SPRI beads (AmpureXP, Beckman Coulter, Brea, CA, USA) were used to purify cDNA, which was subjected to second-strand synthesis using Leader sequence of kappa chain-specific primers, J gene of kappa chain-specific primers and KAPA Biosystems (KAPA HiFi HotStart, Roche, Basel, Switzerland). dsDNA was purified using SPRI beads and VK genes were amplified. Sequencing libraries were quantified with a 4200 TapeStation System (Agilent Technologies), using a D1000 ScreenTape Assay.