Comparison of four different mapping strategies for the association step for three different MPRA libraries (20K-HepG2_P, 80K-neurons, 8K-neurons). From left to right, we present the number of assigned oligos, the number of assigned elements (candidate cis-regulatory elements, reference sequence only), and the number of retrieved variants. A variant is only considered if both the reference and the alternative allele oligos are assigned. The rightmost bars show the number of barcodes per oligo (mean across replicates). The best result for each MPRA library is highlighted in bold in each panel.