Overview of the MPRA design. This schematic shows the selection process of choosing the candidate regulatory sequences to be investigated in the assay (top left), selection of positive controls (top middle), and negative controls (top right). Bottom panel shows an overview of the MPRA steps, including the segment of DNA that is integrated into the cell genome (left), transduction into chondrocyte cell lines (middle), and the downstream sequencing and processing of the MPRA (right).