To study trafficking of bulk internalized vesicles such as macropinosome and lysosome in live cells, an efficient and convenient assay was established according to the axon turning assay. By injecting indicator or fluorescent dyes through a micropipette with air pressure into cell cultures to create a stable gradient around the micropipette tip, vesicles were indicated and labeled. With live cell imaging, the whole process was recorded. Without wash-out of fluorescent dyes and transferring, this assay is an effective, fast labeling system for bulk internalized vesicles, and can also be combined with imaging system.