1. Sources of Variability

2. Cell Types

3. An Experimental Question What are the expression profiles of different cell types in the eye? How do these cells differ? How to they compare to HUVEC cells which come from the human umbilical vein.

4. Biological Samples How would you collect the samples? What sources of variability could you control for?

5. Samples Variability within cell lines, between cultures. Variability between experimental processes

6. Cy3/Cy5 Channel variability? Depends on what sort of experiment we do. Depends on reliability of "platform".

7. With array variability Printing Defects Hybridisation defects Probe strengths

8. Between arrays Different conditions for hybridisation Different detection machines

9. http://www.youtube.com/watch?v=PbODig CZqL8