design: For use with the LHCN-M2 skeletal muscle myocyte cell line, we ported the assembled MPRA block (fragment, barcode, promoter, GFP) to a lentiviral transfer vector (a gift from Nadav Ahituv; Addgene #137725) via restriction cloning (Gordon et al. 2020; Inoue et al. 2017). The University of Michigan Viral Vector Core produced infectious lentiviral particles with this transfer vector and third generation lentiviral plasmids in HEK293T cells. Per replicate, we infected 4 x 10^6 LHCN-M2 human skeletal myoblasts with our MPRA library at an MOI of 10. After infection, we passaged the cells for one week to remove any unincorporated virus or contaminating transfer plasmid, then differentiated the cells for one week. We isolated RNA and gDNA from each replicate using the Qiagen AllPrep DNA/RNA mini kit. We reverse transcribed 30 ug of DNAse I-treated total RNA using SuperScript IV. We performed a cDNA amplification PCR and sample indexing with all cDNA made.