<b>The sensitivity of Cas9 polyclonal antibody assessed by Western blot.</b> Various amounts of recombinant Cas9 (rCas9) were loaded (Lane 3: 0.15 ng, Lane 4: 0.30 ng, Lane 5: 0.625 ng, Lane 6: 1.25 ng, Lane 7: 2.5 ng, Lane 8: 5.0 ng, Lane 9: 10.0 ng, Lane 10: 20.0 ng). Cell lysates prepared from 3.5 x 10⁴ cultured cells (Lane 1: HT1080 cells, Lane 2: HEK 293 cells) were used as a negative control. The blot was probed with Cas9 polyclonal antibody (1:1,000 dilution). For detection, an HRP-conjugated goat anti-rabbit secondary antibody was used (1:5,000 dilution), and signal was detected using ECL reagent.