The gel plug assay is widely used because it is quick and easy to perform, and materials are readily available. The method can be used to evaluate both angiogenic and anti-angiogenic compounds in vivo. Cells containing compounds of interest are added to a cold basement membrane extract such as Geltrex™ and injected subcutaneously into a mouse, where the material solidifies to form a plug. After 7-21 days, depending on the nature of the compound introduced, the plug is recovered and examined histologically for vascular formation.

Assay Description

Quantification can be achieved through sectioning and staining with Masson’s Trichrome, which stains the basement membrane extract blue and the endothelial cells/vessels red, or by measuring the amount of hemoglobin contained in the plug.¹,² 

The primary advantage of this assay is that it is relatively easy to perform; however, it does still require the use of animals which can limit the size throughput. While the subcutaneous locale is a practical choice, it is not ideal since angiogenesis does not typically occur in these areas. The investigator should also note that current measurement techniques are not able to completely compensate for the inherent variability between animals.  




  1. Akhtar N, Dickerson E, Auerbach R. (2002). The sponge/Matrigel angiogenesis assay. Angiogenesis. 5(1-2):75-80.
  2. Kragh M, Hjarnaa P, Bramm E et al. (2003). In vivo chamber angiogenesis assay: an optimized Matrigel plug assay for fast assessment of anti-angiogenic activity. Int J Oncol. 22(2):305-11.

LT173      updated  7-Oct-2011

For Research Use Only. Not for use in diagnostic procedures.