Figure 3. Dumbbell vectors for enhanced gene expression.
Left side. Design of advanced dumbbell vectors: db-luc: basic vector; db-luc-enh: dumbbell featured with the SV40 enhancer; db-int-luc: dumbbell featured with an intron; db-int-luc-enh: dumbbell featured with SV40 enhancer and intron. Right side. Analytical 0.8% agarose gel electrophoresis of the four luciferase dbs after exonuclease treatment. The expected dumbbell bands but no by-products are detected. Numbers of lanes on the right correspond to the dumbbell numbers on the left. M: GeneRuler DNA Ladder Mix (Thermo Fisher Scientific).