PCR Gel ElectrophoresisIntroductionSickle cell disease is caused by a single nucleotide polymorphism (SNP). SNPs are the most common type of genetic variation, with each SNP representing a difference in one nucleotide. SNPs are normally present in a person's DNA. Most often, they are usually found in non-coding regions and have no health effects. When an SNP occurs in a coding region, it may play a direct role in disease by affecting gene function. This SNP for sickle cell disease produces the recognition sequence for a restriction enzyme, HindIII. Samples without SNP (non-disease carriers) do not contain the recognition sequence, and are not cut. This allows digested DNA fragments to be analyzed by separating them using gel electrophoresis, which helps identify whether a patient has sickle cell anemia. Before we can visualize DNA, we need to amplify it. In order to amplify the DNA, we will use a technique called polymerase chain reaction (PCR). With the invention of the PCR technique, DNA profiling has made enormous advances, both in terms of discriminatory power and the ability to recover information from very small (or degraded) starting samples. PCR greatly amplifies the amounts of a specific region of DNA, using primers and DNA polymerase. The PCR method is easily adaptable to analyze STR loci. The PCR method relies on repeated heating and cooling cycles of the reaction for DNA denaturation and enzymatic replication of DNA primers containing complementary DNA in the target region, with DNA synthesis polymerase. the reaction. The DNA polymerase used is normally Taq polymerase because it is very thermostable. As the PCR progressed, the DNA generated ...... middle of paper ...... bands, showing that there was no contamination. These results imply that the experiment was a success since no problems were detected. All five samples were used to increase the reliability of the experiment. PCR without DNA is used as a negative control, no bands were expected which guarantees that there is no effect when there should be none. PCRs with uncleaved DNA should be used to compare cut and uncut DNA. Furthermore, it guarantees that there is an effect when there should be an effect. An improvement to the experiment could be to include a summary containing fragments of known sizes to use as a guide to confirm that the cleaved DNA is the expected size. References http: //peds.oxfordjournals.org/content/13/4/283.full http://ghr.nlm.nih.gov/handbook/genomicresearch/snphttp://www.ndsu.edu/pubweb/~mcclean /plsc431/ students/firas.htm