The experiment that we performed was polymerase chain reaction. We performed it to find what sample matched the unknown sample of DNA that we found at the crime scene. The hypothesis was one of the samples would match the unknown sample. We compared the three known samples against the unknown sample of DNA. We used PCR to allow us to a comparison between the samples by using the position of the bands along the gel. Within the PCR experiment, we used a marker. This moves through the agarose gel by using a flow of electricity. this separates the DNA by the heaviness of each part of the DNA by the number of base pairs. The unknown and the three known samples become fragmented and are then pulled through the gel. The base pairs become separated due to the size of the fragments and the size of the base pairs. This would show the 4 samples and the marker in their size of the fragments. This would allow us to compare the unknown samples to the 3 known samples by the size of the fragments. The result would help us to decide …show more content…
These cycles occur at different temperatures for each of these 3 stages to take place. the denaturing process occurs at 940C. During the denaturing stage of PCR, the DNA reaches its melting point. The heat causes hydrogen bonds between the bases which cause the opening of the DNA. The annealing process occurs around 540C. The primers needed for this process and is usually produced in the lab and line up with the template strand of DNA. Once this occurs it allows a base for the polymerase to attach and then start to copy the DNA. The extension stage occurs at a higher temperature 720C. This creates the best conditions needed so the polymerase bind to the DNA. This produces the second strand which binds together to form the double-stranded DNA. With each cycle that occurs the DNA is then split into 2 bands. with another cycle which can divide again with each cycle, it produces more and more bands. (; ;