Endothelial Tube Formation Assay
Mouse Endothelial Tube Formation Assay (In Vitro Angiogenesis)
Preparing Matrigel:
- Thaw reduced growth factor matrigel (BD: 354234) by submerging the bottle on ice and store the matrigel at 4 °C overnight.
Preparing Cells:
· Wash 90-95% confluent endothelial cells with sterile PBS (1X) without calcium and magnesium twice.
· Incubate cells (on T25 or T75flask) with warm 0.25% Trypsin-EDTA solution (Cell Biologics, Catalog No. 6914) for 3-5 minutes at 37°C. Once cells detach (slightly taps on the flask can be used to speed up the detachment), add 6-10 ml culture medium (Cell Biologics' Cell Culture Medium supplemented with 5-10 % FBS) to the flask to end the digestion (neutralizing the Trypsin).
· Filter the cell suspension through a sterile 40µm nylon mesh filter (BD 352340) to remove remaining clumps.
· Count cells and resuspend cells to a final concentration of 2.5-5.0 x 105 cells/ml in endothelial cell culture medium with 50 ng/ml VEGF.
Tube Formation Assay
· Pipet 200 µl matrigel into each well of a 24-well plate. Avoid creating bubbles.
· Incubate the 24-well plate at 37 °C and 5% CO2 for 30 min to solidify matrigel.
· Once matrigel has set, seed 50,000 cells -100,000(200ul) into each well.
· Observe the tube formation after 4-6 hrs. Peak tube formation may occur between 12hrs and 24hrs.
· Take image by 4X lenses microscope.
Note: Adjust the volume of endothelial culture medium and number of cells plated depending on the type of endothelial cell used.