Can Assays be Interesting? 

Diana Battalgia – Ph.D. Candidate (Microbiology, Immunology, and Parasitology) 

From an outsider’s perspective, the lab is a cold and boring place where things seem to focus on the most obscure of details. While a lot of science is heavily detail-oriented, it doesn’t have to be cold or boring. There are a seemingly endless number of both complex and simple assays that can be performed.

Unfortunately, research is rarely simple. Like other areas of research, vascularization appears to be straightforward; however, while vascularization is the basis of wound healing, it also plays a role in many illnesses including cancer. Therefore, drugs blocking and promoting vascularization have a big place in research and health care. Some of the assays done to illustrate vascularization are fascinating and quite imaginative.

  • CAM (Chick Chorioallantoic Membrane Assay): This assay takes a 3 day old fertilized chicken egg and uses the developing chick embryo to model neovascularization. A small window is cut into the eggshell and a drug, a gel plug, or even cancer cells can be inserted. The effects can be viewed by a camera or by histological staining.
  • Aortic Ring Assay: Using aortas harvested from mice, new vessel formation can be measured and quantified. The aorta is collected and cleaned of all branching vessels and fat before being embedded in a matrix. After a few days, the growth of new vessels can be visualized under a microscope with additional information being provided by staining.
  • Tubule Formation Assay: Endothelial cells plated in a matrix will spontaneous form tubules and organize into a three-dimensional network of vessels. With a time-lapse video, it is possible to watch the migration and replication of these cells as they form a complex honeycomb shaped system. Image J, a program that allows the quantification of visual data, is commonly used to measure the lengths of tubules and the number of nodes formed.
  • Corneal Angiogenesis Assay: The cornea is usually avascular but by cutting a pouch into the cornea and inserting a gel plug or sponge, it is possible to measure the resulting vascularization. Removing the insert and quantifying vessel permeation then measures the effects of a drug placed in the insert.
  • Zebrafish Embryo Model: Zebrafish embryos are a fast and inexpensive method to model neovascularization in vivo. This animal model can be used to screen anti-angiogenic compounds and to track the genetic expression of vessels in the developing eye. Images can be taken under a microscope.

Human biology is so carefully interwoven and complex that it’s nearly impossible to understand a single event without understanding countless others. Assays such as these take into account the complexity of a living system. Many of these assays are used in labs here at LSUHSC.