RNA-seq of PDX tumor: adult male liver cancer tissue
1) mRNA with polyA tail was enriched by Oligo(dT) magnetic beads, and the mRNA was interrupted by metal ion solution treatment method, and the appropriate interrupting temperature and time were selected according to the required fragment size; 2) The first strand of cDNA was synthesized in the M-MuLV reverse transcriptase system using fragmented mRNA as template and random oligonucleotides as primers; 3) After the completion of the one-strand synthesis, the two-strand synthesis and end repair and A-tail were added; 4) T4 DNA ligase was used to catalyze the ligation of the sticky ends of double-stranded DNA with short linkers; 5) The product was purified after adapter ligation with AMPure XP beads, and finally the cDNA of about 300-350 bp was screened to ensure the centralization of the fragments. 6) PCR amplification was performed and the sample index tag was added, and the PCR product was purified again using AMPureXPbeads to obtain the library