Overall Process Video of DNA Fingerprinting Process http://www.youtube.com/watch?v=drC7rR7CIBg
Isolation of the DNA!In order for a DNA fingerprint to be madeyou must first gather DNA from the personyou are fingerprinting.There are many things you could use togather DNA… Human Cheek Cells1. Blood2. Hair3. Skin4. Saliva5. Or any other cell with DNA in it.
Restriction Enzymes• Used to cut DNA into pieces that are specific to each individual persons DNA. • Specific Enzymes cut the DNA into pieces at specific places as well. For Example… • EcoR1 cuts only when the sequence GAATTC occurs.
Restriction Enzymes Continued! • Sticky Ends are made by cutting the DNA in a staggered manner and they have a one stranded DNA sequence that have complementary nucleotides • Blunt Ends are made by cutting the DNA directly down the middle of two nucleotides
Gel Electrophoresis • Samples of cut DNA are placed in an agarose gel • Electricity is added to the gel and the DNA travels to the positive pole and they are spread out according to size.
Transfer to Nylon Screen•Because the gels are so hard tomanipulate the DNA pattern is transferredto a nylon sheet using the process ofsouthern blotting•Nylon is added to the agarose gel andthen a piece of paper is added on top thisabsorbs the DNA bands onto the nylon.
Probing and X-Ray•Probes are radioactive particles thatbind themselves to the main sequence.•Extra probes that are left over areremoved and what is left is only theDNA chain needed to make thefingerprint•This can be scanned by an X-raymachine and it will produce a picture ofthe DNA fingerprint