Fig. 4. Indirect immunofluorescence. C. reinhardtii wild-type strain 124 MT– was probed using primary antibodies against DIP13 or -tubulin and a fluorescence-labeled secondary antibody. DIP13 antibody stains basal bodies (A; bb) and the anterior part of the microtubules (B). An overexposed cell is shown in D to point out punctate staining of flagella (f). Flagellar localization was confirmed by immunoblotting of isolated and detergent-extracted flagella (E; F, whole flagella; M, membrane and matrix fraction; A, axonemes). anti--tubulin antiserum (C; positive control) shows strong labeling of flagella and cytoplasmic microtubules. Exposure times for photographing indirect immunofluorescence were 12 seconds (A, B) or 30 seconds (D) for DIP13 and 5 seconds for -tubulin (C). Bars, 10 µm.