The Pros And Cons Of DNA

Almost every cell in our body contains deoxyribonucleic acid (DNA). DNA can be defined as “a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms…” (University of Utah, 2014). In other words, DNA is a genetic material that contains the information of how cells work. DNA can be used to identify people because everyone has different DNA sequences and varying lengths of DNA. Every human cell contains 3 billion DNA base pairs. We share about 99.9% of our DNA, but the remaining 0.1% is unique. Identical twins are the exception, as they share 100% of their DNA. DNA is made up of A’s T’s G’s and C’s. We all have two sets of DNA which we get from our biological mother and father. When

With todays advances, scientists can get DNA from something as small as a cigarette butt using a technique called Polymerase Chain Reaction (PCR). PCR is a tool that focuses in on a segment of DNA and then copies it billions of times. PCR was discovered by Dr. Kary Mullis. “The copying process, known as polymerase chain reaction (PCR), uses an enzyme (polymerase) to replicate DNA regions in a test tube. By repeating the copying process, a small number of DNA molecules can be reliably increased up to billions within several hours.” (National Institute of Justice, 2012). PCR is also helpful as it can accurately analyze poor samples that may have one from dirty crime scenes, or that are just really

First, DNA from an evidence sample has to be isolated from that that sample, and eventually, DNA has to be taken from an individual who is a suspect in the case at hand. The DNA is extracted from the crime scene or person and then the size of the DNA sample is determined. As aforementioned, DNA is made up of A’s, T’s, G’s and C’s. At a certain point, the letters tend to repeat. This set of letters is known as Variable Number of Tandem Repeats (VNTR’s). Similar to VNTR’s are Short Tandem Repeats (STR’s). VNTR sequences (10-100 base pairs) are much longer than STR’s (2-9 base pairs). STR’s are more useful because they can be amplified by PCR’s, which gives scientists more to work with when they have a small sample of DNA. Any biological DNA that has been stored dry or frozen can also be used as a sample. Second, DNA has to be processed so that test results can be generated. After the STR’s are detected, the number of repeats in the DNA sequence are determined, which is known as sample genotyping. Lastly, the results are compared to determine whether to not the sample is a match to that of the