For generation of stable cell lines, 2.5 × 105 293T cells were seeded onto 60 × 15 mm tissue culture dishes. In all, 1.25 μg of pLKO.DEST.puro plasmids containing the cloned ORF of METTL2A, 2B, 6, DALRD3, and DALRD3 truncations or empty vector along with a lentiviral packaging cocktail containing 0.75 μg of psPAX2 packaging plasmid and 0.5 μg of pMD2.G envelope plasmid was transfected into HEK293T cells using calcium phosphate transfection. In all, 48 hours after transfection, media containing virus was collected and filtered sterilized through 0.45 μm filters and flash frozen in 1 ml aliquots. Lentivirus for the pLJM-EGFP or codon reporter plasmids were generated in an identical manner.
