1. What DNA processing technique does STR use??
The system of DNA profiling used today is based on PCR and uses simple sequences or short tandem repeats (STR). This method uses highly polymorphic regions that have short repeated sequences of DNA (the most common is 4 bases repeated, but there are other lengths in use, including 3 and 5 bases).
2. What enzymes do Gel Electrophoresis, PCR, and RFLP use.
Restriction enzymes are used to cut the DNA prior to performing gel electrophoresis. PCR requires a DNA polymerase enzyme that makes new strands of DNA, using existing strands as templates. RFLP uses methylation-sensitive enzyme.
3. What issue do blobs present to DNA analysts who are examining electropherograms.
Issues with DNA Analysis: These challenges include the adequacy of population studies and testing methods, the role of human error in interpreting test results, alleged unfairness to criminal defendants and the lack of standards.
4. Describe the process of PCR including the three stages and methods used to accomplish each stage.
PCR is based on three simple steps required for any DNA synthesis reaction: (1) denaturation of the template into single strands; (2) annealing of primers to each original strand for new strand synthesis; and (3) extension of the new DNA strands from the primers.
5. Describe the process of gel electrophoresis. Include how it works and the end result.
Gel electrophoresis is a technique used to separate DNA fragments according to their size. DNA samples are loaded into wells (indentations) at one end of a gel, and an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode.