Construct a flow chamber as shown in the video. Make sure that the parafilm seal is tight and use washed coverslips.Incubate actin-binding agent in the chamber for 5-10′.Block non-specific binding sites on the glass coverslip with a blocking protein.Polymerize actin inside the chamber by flowing in G-actin in polymerizing buffer.Washout unpolymerized actin by flowing in excess buffer.