The microtubule coil contains both stable and dynamic microtubules. (A) Immunofluorescence analysis of mouse platelets using antibodies to Tyr-tubulin, Glu-tubulin, and acetylated tubulin indicates that all 3 modified tubulin forms exist in the marginal band. Cells were double-labeled with an antibody to β1-tubulin. (B) Immunofluorescence analysis of mouse platelets using antibodies to Tyr-tubulin (top panel) and acetylated tubulin (middle panel). Note that both isoforms accumulated within platelet marginal bands, although some platelets appear to label more strongly with one antibody than with the other (bottom panel). (C) Western blot of mouse platelet lysates; equal protein quantities were loaded and probed with antibodies to Glu-tubulin (glu), acetylated tubulin (ace), and Tyr-tubulin (tyr).