Fig 1: Prepare FGF10 soaked bead and needles for migration assay(A–A'') Heparin beads of different brands. (A) from sigma company, Cat#H5263, (A') from Abcam company, Cat#ab193268, and (A'') from ADAR Biotech company, Cat#6024.(B) A stereo microscope used to pick up suitable beads, organoids and to set up the migration assay.(C) The zoom knob was set at 3 for all steps.(D and D') Picture of Heparin bead 100 µm (D) and 150 µm (D').(E) A 100 µm and a 150 µm beads were sealed in PBS in a 35 mm dish. These two beads will serve as a reference for picking beads and setting up steps.(F) Picked beads in a 0.2 mL tube and suspended in 20 µL of FGF10 solution. When upside down, the solution should not move along the tube wall, yet the bead will move freely in the solution.(G) 0.2 mL tube containing the picked beads was secured in a capless 1.5 mL tube with tape.(H) the 1.5 mL tube was rotated on a mixer.(I) Steps of preparing needles for migration assay.