Cellular Angiogenesis Assay Services

The Cellular Angiogenesis Assay allows for the evaluation of pro- or anti-angiogenic effects of drugs on human endothelial cell vessel formation capacity.

Angiogenesis, the formation of new blood vessels, is a physiological process during growth and development. Beyond that, angiogenesis is necessary for tumor growth and is involved in other pathological disorders (e.g. psoriasis, macular degeneration). The Cellular Angiogenesis Assay mimics the in vivo situation with respect to the first stages of the angiogenic cascade.

  • Vessel sprouting can be induced by VEGF-A, FGF-2, HB-EGF, deferoxamine or others
  • The spheroids used in the cell-based angiogenesis assay generate sprouts that are close to the physiological arrangement of endothelial cell vessels
  • A matching in vivo model is available at Reaction Biology for seamless in vivo transition

Vessel sprouting

Endothelial cell spheroids will sprout new capillary-like vessels when stimulated with pro-angiogenic factors like VEGF-A.

The number and length of the sprouts correspond to the angiogenic activity of the endothelial cells. Pro-angiogenic compounds induce sprouting; whereas angiogenesis inhibitors prevent new vessel formation.

vessel sprouting example

Additional Information

Assay Procedure


cellular angiogenesis assay procedure


Endothelial cells aggregate to form spheroids in a hanging drop system. The spheroids are pipetted into multi-well plates in a collagen matrix where the test compounds and stimulation factors are added. During a 24-hour period, vessels sprout from the spheroids and are quantified by measuring their length to determine the cumulative sprout length.

Example data

EC sprouting Example data

The angiogenesis inhibitors PTK787 and sunitinib were tested for inhibition of endothelial cell sprouting (VEGF-A or deferoxamine induced) and fibroblast scattering. The selective inhibitor PTK787 is active on endothelial cell sprouting but does not effect fibroblast scattering. In contrast sunitinib, which has a broader kinase inhibition profile than PTK787, inhibits both endothelial cell sprouting and fibroblast scattering.

Stimulating factors

Stimulating factors

Comparison of pro-angiogenic factors. Stimulation of vessel sprouting after a 24-hour incubation with a variety of pro-angiogenic factors.

Screening Formats

Setup: IC50 value determination and single concentration testing are possible. Drug combination treatment is an option.

We offer a variety of stimulating factors for the induction of vessel sprouting such as VEGF-A, deferoxamine, FGF-2, HB-EGF, and more.

Testing of pro- and anti-angiogenic drug candidates is possible.

Controls: Stimulus-free media only is the low control of vessel sprouting. VEGF-A only is the high control. Treatment with a reference inhibitor is included to ensure quality control.

Report: A detailed report including assay conditions, methodology, and comprehensive evaluation of data as well as raw data for each analysis will be provided. Photographs are optional.

Turnaround time: Results will be available within about 3 weeks.

Screening facility: The assay is performed in Freiburg, Germany.

Compound requirements: In brief: 100 µl of the stock solution with 100x of the highest assay concentration or the equivalent of solid material.