1. 2005-2006 LAB 6 DNA FINGERPRINTING

2. BUILD the GEL FRAME 2005-2006 Position comb and lock in place in side slots

3. 2005-2006 Let it sit undisturbed until it cools and solidifies Remove comb by pulling STRAIGHT UP Carefully remove ends

4.  Place rack containing gel in tank  Add buffer to cover gel  Load samples in wells  Place lid on tank  Connect electrodes  Turn on current  Watch for bubbles 2005-2006 http://www.rapidonline.com/netalogue/zoomed/Large/M079061W01.jpg

5. 2005-2006 Where do we get DNA?  REMEMBER WHERE DNA IS FOUND Example: not in hair itself (keratin protein), but in follicle cells attached to hair CELL NUCLEI  DO ALL CELLS WORK?  OTHER PLACES COULD GET CELLS?  NEED CELLS  In mammals RED BLOOD CELLS have NO NUCLEI  Saliva  Semen

6. 2005-2006 Cut DNA  Restriction enzymes  restriction endonucleases  discovered in 1960s  evolved in bacteria to cut up foreign DNA (“restriction”)  protection against viruses & other bacteria  bacteria protect their own DNA by methylation & by not using the base sequences recognized by the enzymes in their own DNA

7. 2005-2006 Gel Electrophoresis  Separation of DNA fragments by size  DNA is negatively charged  moves toward + charge in electrical field  agarose gel  “swimming through Jello”  smaller fragments move faster cut DNA with restriction enzymes

8. 2005-2006 Gel Electrophoresis

9. 2005-2006

10. Measuring fragment size  compare bands to a known “standard”  usually lambda phage virus cut with HindIII  nice range of sizes with a distinct pattern

11. 2005-2006 RFLP  Restriction Fragment Length Polymorphism Restriction Fragment Length Polymorphism  differences in DNA between individuals  change in DNA sequence affects restriction enzyme “cut” site  will create different band pattern

12. 2005-2006 Polymorphisms in populations  Differences between individuals at the DNA level