cathepsin-activatable Cy5 fluorescent imaging probe LUM015

A cathepsin-activatable fluorescent probe with imaging activity. The cathepsin-activatable fluorescent probe LUM015 contains the Cy5 fluorophore linked, via a pan-cathepsin protease cleavable peptide, to a fluorescent quencher. Upon injection, the peptide in LUM015 can be cleaved by cathepsins overexpressed by tumor cells, which releases the quencher and activates the fluorophore. Upon imaging, tumor cells expressing cathepsin family proteases can be detected.