3) Experimental Systems in Biology

• We can study a range of cellular behaviour such as

  1. Cell Migration
  2. Cell Adhesion
  3. Cell proliferation
  4. Cell death
  5. Cell Communication
• Describe how a Transwell Assay is used to analyse cell migration:

  1. A culture insert with a porous membrane is placed in a well
  2. Cells are placed onto the top of the porous membrane in the insert.
  3. A chemoattractant is used in the lower compartment to stimulate cell migration
  4. After incubation period, cells that have migrated through the membrane are fixed and stained.

  
• Immunofluorescence can be used to identify the presence of proteins in proliferating cells (eg: Ki-67). The proliferating positive cells can then be counted in different samples.

  
• % of cells proliferating = (proliferating cells / total cells)*100

  
• Cell death can be analysed by viability markers.

  When cells die, their membrane becomes permeable to some florescent dyes.

  The dye binds onto DNA and can be counted.