Fig. 4.
Fluorescence microscopy and flow cytometry of wild-type C. reinhardtii treated with FAM-streptavidin, FAM-streptavidin and nonaarginine (with no biotin), or FAM-streptavidin:biotin-R9 complex. (A, C) Cells treated with a FAM-streptavidin:biotin-R9 complex show internalization as well as cell wall binding. (B) Cells treated with the control FAM-streptavidin at the same concentration show no indication of binding or uptake. (D) Graph of the mean fluorescence from flow cytometry indicates the level of uptake for the noncovalent FAM-streptavidin and nonaarginine mixture vs. FAM-streptavidin:biotin-R9 complex. (A, C) Scale bar equals 5 μm.