Microtubule plus ends visualized with EB1-GFP in plant cells

The plus end binding protein EB1 (End-Binding 1) primarily decorates growing microtubule plus ends when fused to green fluorescent protein (GFP). We can use this as a tool to determine the polarity of different microtubule arrays. Shown here is the interphase cortical array, which consists of microtubules of mixed orientation, that are anchored along their lengths to the cell cortex. The movie is a time-lapse speeded up 35x real time, and shows images captured at 5 second intervals with an epifluorescence microscope. The cell is a cotyledon epidermal cell from an arabidopsis thaliana seedling. The bar is 5 microns.