Summative 4 DNA fingerprinting is a technique used in a lab to find the suspect of a crime scene using DNA samples. The DNA profile of the crime scene has to match the DNA profile of the suspect to solve the case, and that is where gel electrophoresis comes in play. DNA is first extracted from samples of cells, like the skin, blood, saliva, hair, or anything that contains DNA, which then becomes purified. Then proteins cut at specific parts of the strand, which are known as restriction enzymes. The restriction enzymes form bands on the gel, sorted by length based off of the electric current. Nucleic acid molecules are separated when placed in a chamber with an electric field that moves the negatively charged molecules through the agarose. DNA is polar since it has a highly charged phosphate backbone, making it soluble in water. Because DNA is negatively charged, it will move towards the positively charged electrode when an electric current is applied. Shorter strands move more quickly than longer strands if gel, which is why the bands are placed in order of size on the gel. An example of using electrophoresis in real life is a real life case. The Minnesota Bureau of Criminal Apprehension (BCA) did a blood test on the jeans, shirt and blood samples from two people, Schwartz and Coonrod, who were involved in a murder case. These tests confirmed the blood stains on the jeans and shirt were consistent with Coonrod's blood type from the DNA …show more content…
The frequency of this DNA banding pattern in the Caucasian population is approximately 1 in 33 billion. Although no definitive conclusion can be reached, it is the opinion of the undersigned that the DNA banding patterns obtained from the stain removed from the blue jeans and the blood of Carrie Coonrod are from the same individual (State v.