The procedure of PCR is useful because sometimes, during DNA tests and sampling procedures, more DNA than what is available is required. Biochemists find it very useful when they have large number of replicas of the DNA or nucleotides they are working at. Hence, they do not find it difficult finding the DNA, recognizing it during their experiments, and working with it.
Restriction enzymes are used to separate the desired DNS from all others in case PCR is not applicable or recommended. These enzymes cut down segments of genomic DNA at particular nucleotide sites. To separate these DNA fragments, electrophoresis procedures are used. Small diameter capillary array gel electrophoresis provides quicker separation of fragments by the application of electric fields. This technique, which in this case is called pulse field gel electrophoresis (PFGE), involves many ways, one of which is electro elusion which involves the use of multiple electrodes located orthogonally from the agarose gel containing DNA which is sealed in a dialysis tubing containing buffer. Small pulses of alternate current are passed all the way through this gel, which results in gene separation from the gel piece. The DNA is still in the dialysis tubing, so it is easily discoverable. Another way of recovering the DNA from the gel is by using agarase to digest the agarose, which leaves behind the desired DNA which we can separate easily.
16s rRNA gene sequencing is used for the identification of bacteria and studying of bacterial phylogeny and taxonomy. The reasons why DNA sequencing can be used for this purpose are many. First of all, 16s rRNA gene is present in nearly all bacteria. DNA sequences are not found in other organisms. Second, since the functionality of 16s rRNA has not altered with time, this means that we can use its sequence changes as an accurate measure of time or evolution. In other words, when we have to identify a lot of diverse types of organisms, we require two main ...Show more