Localization and intracellular motility of myosin IIB (MIIB) in protrusive regions of migrating CHO.K1 cells. This Video corresponds to Fig. 6 B and video 4 in JCB 183:543-554 , 2008. Images of GFP-MIIB (green) and RFP-actin (magenta) were collected every 4 s using TIRF microscopy with 10 frames/s shown. Images were acquired in an inverted microscope (model IX70;Olympus). GFP and RFP were excited using the 488-nm laser line of an Ar ion laser and the 543-nm laser line of a He-Ne laser (Melles Griot), respectively. For dual GFP- mRFP/mCherry/mOrange, a dual-emission filter (z488/543) was used. Images were acquired with a charge-coupled device camera (Retiga Exi; Qimaging) and analyzed using MetaMorph software (MDS Analytical Technologies).