PRATICAL WORKSHEETS Essay Example | Topics and Well Written Essays - 500 words

PRATICAL WORKSHEETS - Essay Example The DNA samples collected from suspects have the similar size of bands of about 1000 to 1100bp. However, band size of about 800 to 900bp and 1300-1400bp were also seen in the samples 1 and 2. On the other hand, the DNA fingerprinting shows that suspect 3 DNA has base pair band size of about 600-700bp that is similar to the band size of the DNA attained from the crime sight. Thus, is it quite clear that the DNA samples from the crime sight and suspect 3 DNA samples are same and suspect 3 has interaction with the crime sight. 3. Tris-borate-EDTA and Tris acetate-EDTA are the basic buffing compounds that are used to characterize the DNA molecules. Tris acetate-EDTA is to characterize smaller molecules of DNA whereas Tris-borate-EDTA is taken to analyze the portions of DNA. In order to maintain the pH of the DNA fragments, DC voltages of about 4-10V per centimetre is applied. On the other hand, it also enhances the DNA fingerprinting by lowering the movement of portions of DNA. In this way, bands with enhanced visibility and broad view can be created. On the other hand, as the concentration of gel increases the movement of fragments also decreases. Molecular biologists use DNA electrophoresis and find it a better method to differentiate different DNA fragments, as different segments of the DNA molecule show different characteristic when charge is applied. The DNA matrix is first into a solution that has higher concentration of buffer and DC voltages are then passed. As the presence of phosphate groups makes the DNA molecules to have negative polarity, it attracts the positive terminal. The ratio of the mobility depends on the strand size of the DNA molecule. If the strand size of the DNA is smaller it will move easily and faster after applying electric current as compared to the longer stands DNA. In order to make the DNA samples more visible a florescent compound like ethidium bromide is added to make the