View source for DNA Sequencing

<p><span style="font-size:24px"><strong><u>DNA Sequencing</u></strong></span></p>

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<p><strong><span style="font-size:20px">What is Sequencing?</span></strong></p>

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<p><span style="font-size:14px">Sequencing is the method&nbsp;to determine&nbsp;biopolymer&#39;s primary sequence.&nbsp;Sequencing results in a linear string of symbolic letters&nbsp;which&nbsp;summarize important information of genome by genetic code&mdash;A, T, G, C.</span></p>

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<p><span style="font-size:20px"><strong>Why sequencing is important?</strong></span></p>

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<p><span style="font-size:14px">Sequencing is a process to&nbsp;figure&nbsp;out the order of biopolymer such as DNA nucleotides and&nbsp;bases. As we understand the sentence, not only the sequence of the letters but also grammar and the decoding process are required.&nbsp;Similarly, the genome&nbsp;is more than just string of successive letters. Sequencing the genome is an important process in order to understand the meaning of it.&nbsp;Researchers think that studying genome sequence&nbsp;will be helpful for understanding the work of the gonome&mdash;how genes work together to direct and regulate the function of cells such as&nbsp;growth, differentiation&nbsp;and maintenance. Finally, portion of&nbsp;genes account for less than&nbsp;25 percent of the entire genome. Therefore, figuring out&nbsp;the entire genome sequence will be helpful to&nbsp;study the rest parts of the genome except&nbsp;the genes. This region contains the regulatory regions that control gene expression, as well as long stretches of junk DNA&mdash; region of genome with&nbsp;unknown function.</span></p>

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<p><span style="font-size:20px"><strong>How sequencing is operated?</strong></span></p>

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<p><span style="font-size:14px">It&#39;s almost impossible to sequence whole genome at once since existing DNA sequencing methods are limited in handling short-stratches at a time. As a result, researchers break down the genome into small fragments and reasseble these fragments into order of&nbsp;original long string. The process of transition&nbsp;of fragmented reads into a long and continuous sequence is assembly. Assembly or alignment takes more time than the sequencing.</span></p>

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<p><span style="font-size:20px"><strong>Which kinds of sequencing techniques are available?</strong></span></p>

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<p><span style="font-size:14px">&ldquo;Illumina&rdquo; licensed&nbsp;sequencing technology using nanopores&nbsp;from Oxford Nanopore Technologies. For sequencing determination,&nbsp;Illumina sequencing system use&nbsp;reversible terminators.&nbsp;Single molecules of DNA are attached to a flat support material, amplified in situ and used as templates for synthetic sequencing with fluorescent reversible terminator deoxyribonucleotides. Another possible way to&nbsp;sequence&nbsp;is by using fluorophore technology. &quot;Pacific Biosciences&quot; is currently SMRT (Single Molecule Real Time) DNA sequencing technology. SMRT sequencing is a harnesses the natural process of DNA replication and can&nbsp;real-time observation of DNA replication by using phosphorlinked deoxyribonucleotides.</span></p>

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<p><span style="font-size:20px"><strong>References</strong></span></p>

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<ol>
	<li><span style="font-size:14px">https://en.wikipedia.org/wiki/Sequencing</span></li>
	<li><span style="font-size:14px">http://www.genomenewsnetwork.org/resources/whats_a_genome/Chp2_1.shtml</span></li>
	<li><span style="font-size:14px">N/A. (2008). Accurate Whole Human Genome Sequencing using Reversible Terminator Chemistry. <em>Nature.</em> <em>456</em>(7218): 53&ndash;59.</span></li>
	<li><span style="font-size:14px">Xiaoge, G., Kevin, L., Karen, O., Jenny Z., Sandeep S. D., &amp; Sue J.R. (2015). SMRT Sequencing for Parallel Analysis of Multiple Targets and Accurate SNP Phasing. <em>G3</em>. g3.115.023317</span></li>
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