Bulky molecules, such as COSAN, may have slow DNA-binding kinetics because they must overcome structural barriers and need extensive DNA unwinding. Accordingly, we repeated the UV-Vis and CD measurements of ctDNA and ctDNA with COSAN ([COSAN]/[ctDNA(pb)] ratio from 0 to 0.5) after seven days of incubation at room temperature (Figure and S4). Nevertheless, we observed no differences in either the UV-Vis or CD spectra of ctDNA after adding COSAN. These results indicate that COSAN does not interact with ctDNA.