The iClick™ EdU Andy Fluor™ 555 Imaging Kit is a superior alternative to the traditional BrdU cell proliferation assay that is optimized for fluorescence microscopy applications. In this assay the modified thymidine analogue EdU is efficiently incorporated into newly synthesized DNA and fluorescently labeled with a bright, photostable Andy Fluor™ dye in a fast, highly-specific click reaction. This fluorescent labeling of proliferating cells is accurate and compatible with antibody methods due to the mild click protocol.