title: hds_RNA_L2
design: 1.The mRNA is captured using oligo dT magnetic beads. 2.mRNA is interrupted by Mg2+. 3.The interrupted mRNA is reverse-transcribed into a short cDNA using random primers. 4.Perform end repair and A-tailling addition. 5.cDNA is ligated with adapter and purified. 6.PCR amplification and purification are performed. 7.Cyclization reaction is performed to construct a DNB sequencing library.