RNA-SEQ assay for wild type and CRISPR induced endoglin knockout human pulmonary artery smooth muscle cells (PASMC)

The goal of this study is to investigate the differential transcripted genes affected by CRISPR induced endoglin knockout in PASMC cells. Total RNA was purified from NTC or ENG-/- PASMC cells using RNeasy Mini Kit (Qiagen, Hilden, Germany). RNA quality and concentration were assessed with Agilent Tapestation 200 (Agilent Technologies) and Qubit 2.0 (ThermoFisher Scientific). ~250-500 ng RNA were used for library construction. The NGS libraries were constructed using the KAPA Stranded mRNA-Seq Kits (KapaBioSystems). mRNA was captured using magnetic oligo-dT beads and 1st strand cDNA was synthesized using random priming. In order to preserve strand-specificity, 2nd strand synthesis, which converts the cDNA:RNA hybrid to double-stranded cDNA (dscDNA), was marked by dUTP incorporation. cDNA framents were A-tailed by adding dAMP to the 3'-ends of the dscDNA library fragments. dsDNA Illumina TruSeq "forked” adapters 3'-dTMP overhangs were then ligated to A-tailed library insert fragments. Each of the six libraries were ligated with a unique Truseq 6bp barcode. Library fragments were amplified using the KAPA HiFi HotStart polymerase. The strand marked with dUTP was not amplified, allowing strand-specific sequencing. Fragment length and library quality was assessed on a 2100 Bioanalyzer using the High Sensitivity DNA Kit (Agilent Technologies). Libraries were diluted to 10nM and pooled at equimolar ratios. The pool was then diluted to 2nM and denatured in NaOH following Illumina recommendations. 10pM of denatured library pool was loaded in one HiSeq lane and flowcell was clustered on the Illumina C-bot. 5% PhiX control was spiked-in. The flowcell was sequenced on a HiSeq 2500 V4 chemistry with 50bp Single read protocol. Data was demultiplexed and Fastq files were generated using BcptoFastq 1.8.4 script provided by Illumina.