The protein clathrin, which was first isolated in 1975 by British scientist Barbara Pearse, is best known for its triskelion form and its important role in coated vesicle formation. The formation of coated vesicles is an uninterrupted and essential process in non-dividing cells. However, clathrin also performs a vital function of a different sort in cells undergoing mitosis. Once cell division initiates, clathrin halts its role in vesicle transport and binds to microtubules and microtubule-associated proteins present in the mitotic spindle. There clathrin is key to providing strength and stability to the spindle fibers. The dynamic behavior of coated vesicles was visualized in the digital video sequences in this section by fusing mEmerald to clathrin in a specimen of fox lung cells. The Golgi apparatus was also targeted through the use of mApple fused to a Golgi targeting signal.