With the same example as paternity testing law, enforcement agencies are able to use DNA to identify unknown people such as John Does. Other uses of DNA fingerprinting are being used to understand history and evolution of the human population (1). Works Cited Krawczak, Michael, and J. Schmidtke. DNA Fingerprinting. 2nd ed.
The enzymes fragment foreign DNA at specific locations depending on the base sequence (Griffiths, 1996). In order to analyze an organism’s genome a researcher will add a certain restriction enzyme to DNA. This produces small restriction fragments of DNA that vary in length. Electrophoresis is then used to separate out the various fragments of DNA. This is accomplished by subjecting the fragmented DNA to an electrical charge after it has been placed onto an agarose gel plate.
The samples of DNA were obtained by plucking individual hairs from students' heads and using the PCR device to replicate the DNA from the roots of the hair. The replicated DNA samples were then placed into the electrophoresis gel and the device was turned on. Using the methods discussed above we found that three of the fourteen samples, 21%, were homozygous and the remaining eleven samples, 79%, were heterozygous. We concluded that it is possible to examine small amounts of DNA by first replicating the sample using Polymerase Chain Reactions then using gel electrophoresis to determine the genotype of the DNA. The main goal for our experiment was to learn how to examine DNA when there is only a small sample present.
There are several steps taken when analyzing DNA in forensics. When testing scientists must first isolate the DNA so it is not contaminated and can't be used. Lab technicians the take small pieces of the DNA, conserving as much as they can encase they need to test again. Once testing is done the next step is determining the DNA test results and finally there is the comparison and interpretation of the test results from the unknown and known samples to determ... ... middle of paper ... ...'t show that it was of the victims. The court ruled that extensive discovery requirements for future proceedings, including copies of lab results and reports; explanation of statistical calculations; explanations of any observed contaminants; and chain of custody documents (PBS, 1996) .
Polyacrylamide gels are usually used for proteins and for small fragments of DNA. I will focus more on the agarose gel. Agarose ... ... middle of paper ... ...gel-electrophoresis/6530 DNA Learning Center. Biology Animation Center: Gel Electrophoresis. Retrieved 12-21-2013 from Cold Spring Harbor Laboratory, website: http://www.dnalc.org/resources/animations/gelelectrophoresis.html Espionage Information.
With the use of restriction fragment length polymorphism (RFLP) technology in DNA fingerprinting, the sorted double-stranded DNA fragments were then subjected to a blotting technique in which they were split into single strands and transferred to a nylon sheet. The next important scientific discovery is autoradiography. It is the making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object (Merriam-Webster, 2018). In 1867, Niepce de St. Victor accidentally obtained the first autoradiograph. He observed that the uranium nitrate caused the blackening of silver iodide and silver chloride emulsions (Introduction to Autoradiography: History, 2018).
Gel electrophoresis is executed by injecting the DNA fragments into a gel, (agarose),and then running an electrical current through the gel causing the fragments to travel, the shorter the fragment, the farther it travels. The gel is... ... middle of paper ... ...etermine whether a product is fresh or processed. This can be derived from PCR testing due to the results of PCR testing being close to 100% sensitivity and specificity. Another application of PCR is in a crime scene investigation in New Jersey in 1994. The criminal’s DNA was old an not as reliable or as abundant as it needed to be.
Michael Beirne Mrs. Parks Honors Biology 11 April 2014 DNA Fingerprinting and PCR DNA fingerprinting, or sometimes known as DNA typing, is isolating and developing images of sequences of DNA to evaluate the DNA in an individual’s cells. DNA fingerprinting today is used for many different things in many different areas of science. In forensic science, DNA typing can determine which person did which crime by using blood or skin left at a crime scene. In medical science, patients can find out who their siblings, parents, or children are by using DNA fingerprinting (webmd).
The purpose of this process is to access the persons DNA, those fibers are DNA. The DNA will be sheered into fragments to get its sequence. DNA contains chemical known by their first letters, A T C and G. Mutation or damaged genome trace the what kind of disease the person have. After sequencing the decoded genome, the genesis must figure out what it all means, they compare the patient’s genome with thousands of others, mainly by the reference genome. If the genome is different, then it could mean that the change is unique to the patient.
As seen on many crime shows and at real-life crime scenes, it is necessary to be able to identify DNA. Most of the time, this is done using a technique known as gel electrophoresis. Gel electrophoresis is a method used to separate the macromolecules that make up nucleic acids, such as DNA and RNA, along with proteins. Gel electrophoresis is significant because it has given scientists insight on what cells cause certain diseases and has led to advancements in DNA and fingerprint identification. My experiment will use gel electrophoresis to compare samples of natural and synthetic food dyes.