Fig. 5.

Fluorescence microscopy of wild-type C. reinhardtii showing delivery of an active enzyme. Wild-type cells were treated with (A, B) HRP-streptavidin:biotin-R9 complex, (C, D) HRP-streptavidin and nonaarginine mixture, and (E, F) HRP-streptavidin alone and incubated with a chemical detection reagent for HRP (HRP substrate) that is converted to a fluorescent product after turnover by the enzyme. Only cells treated with HRP-streptavidin:biotin-R9 complex followed by the HRP substrate show any fluorescent signal. (G, H) Wild-type cells treated with HRP-streptavidin:biotin-R9 complex and not treated with the HRP substrate showed no fluorescence. Microscope settings were the same for all high-resolution images and all low-resolution images, respectively.