Experimental strategies to enrich for full-length RNA molecules in LRS data. (A) Methods that specifically enrich for 5′ ends or full-length molecules (based on size or sequence) can be used to increase the chances of sequencing full-length mRNAs. (B) Methods that add known sequences to the terminal ends of mRNAs by ligation (left) or tailing (right) are an unbiased way to recognize full-length molecules in both cDNA (top) and directRNA (bottom) sequencing. (C) Circularization of mRNAs or cDNAs during library preparation allows for multiple rounds of terminal adapter and target molecule sequencing.