(a) Fluorescent microscopy of peptide binding to SKOV-3, OVCAR-3, MDA-MB-435, and HEK293 cells. Cells were incubated with 10 µM biotinylated J18, J24, or PBS for 1 h at 37 °C. Bound peptides were probed by a mouse monoclonal anti-biotin antibody and detected using an epifluorescent Nikon T1-SM inverted microscope (Nikon, Melville, NY, USA). (b) The corrected total cell fluorescence was determined using ImageJ software. Results showed that peptide J18 displayed higher fluorescence compared to PBS (vehicle) for SKOV-3 and OVCAR-3 cells. Peptide J24 demonstrated higher fluorescence to SKOV-3 cells. A p-value of < 0.05 was considered significant. **** p < 0.0001. Red (cy3-peptides).