1. Microarrays

2. Microarrays Used to observe which genes are expressed in cells
1-DNA segments are taken of specific genes and placed on a DNA “chip” or slide
2-mRNA from tissue samples are then converted back to DNA and each type of tissue is then “labeled” usually with a color-cDNA
3-Hybridize the genes-mix the cDNA with the gene segments on the slide, if they match the color will appear and that gene is expressed. If there is no match, the color will not appear. If there is a slight match, a color will appear but will not be the color the cDNA was labeled with.

4. Microarray movie clip http://www.youtube.com/watch?v=VNsThMNjKhM

5. How is this helpful? Can determine genes involved in cancer
Can make a “pre-test” for cancer
Can determine genes expressed in two types of tissues under different conditions
**Also used to determine if you have been infected with a virus…

6. DNA Microarray Lab Results
Gene Description
Color of Spot
Gene is expressed more in lung cancer cells than in normal lung cells
Pink
Gene is expressed in both lung cancer cells and normal lung cells
Purple
Gene is not expressed in in either lung cancer cells or normal lung cells
Colorless
Gene is expressed more in normal lung cells than in lung cancer cells
Blue