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Shot Gun Sequencing Research Paper

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Shot-gun sequencing is specifically utilized to sequence large amounts of DNA, with long sequences. Shot-gun sequencing is a process used for the identification of overlapping regions in DNA, through the process of randomly breaking DNA sequences into smaller pieces, followed by DNA sequence reassembling into original order based on DNA sequence overlaps, to produce the complete sequence. The DNA sequences are broken down into smaller pieces using restriction enzymes or through the process of shearing. This is followed by the alignment of overlapping sequences using computer technology. Shot-gun sequencing is advantageous as it directly performs decoding of the genome and does not require a physical map, and is therefore a relatively rapid …show more content…

A type of next-generation sequencing is illumina sequencing. Illumina sequencing sequences large amounts of DNA in a single attempt. In this process, the sample is firstly cleaved into short fragments. Then, PCR is performed in order for amplification of each read to be carried out. This would subsequently lead to the creation of numerous copies of the same read, at a particular location. Then, separation into single strands occurs, so that sequencing can be performed. This process is followed by the introduction of fluorescently labeled nucleotides and DNA polymerase into the slide, with a termination so that one base is added each time. Therefore, at each read location, a fluorescent signal would be present to indicate the addition of a base. Then, another cycle is performed, with the terminators and fluorescent signals being removed so that another base can be added and to prevent the signal from interfering with future cycles. Computer technology is then utilized to detect the base at each site, so that a sequence can be constructed. This will result in sequence reads of the same length since the same number of cycles will be performed for each …show more content…

Firstly, shot-gun sequencing requires a large portion of template DNA for each read, and subsequently, numerous strands of template DNA are required for each read since a strand that terminates on each base is required for the construction of a complete sequence. However, a sequence can be achieved through a single strand using next-generation sequencing. Also, next-generation sequencing is a faster process than shot-gun sequencing since the chemical reactions taking place in next-generation sequencing can be merged with signal detection, which cannot be done with shot-gun sequencing, and next-generation sequencing allows more DNA to be read on a single run than compared to shot-gun sequencing. Additionally, next-generation sequencing results in reduced costs since not as much human labor and reagents are required as those needed for shot-gun sequencing. Furthermore, next-generation sequencing is more accurate than shot-gun sequencing as next-generation sequencing involves numerous repeats due to the need for each read to be amplified before sequencing and its dependence on numerous short overlapping reads, in order for multiple sequences of DNA and RNA to be achieved. Also, due to its cheap costs, it would be more economical to perform multiple repeats rather than shot-gun sequencing, whose costs are exceedingly greater. Therefore, due to

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