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<p><em><span style="font-family:times new roman,times,serif"><span style="font-size:22px"><strong>&nbsp; Sequencing</strong></span></span></em></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif"><strong>&nbsp; </strong><u><strong>Definition</strong></u></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; Sequencing is an analysis of biopolymer such as DNA, RNA, and protein for finding out the exact structure (atomic-level). RNA sequencing is a process of ordering and lining the nucleotides &nbsp; &nbsp; &nbsp; in given structure. Although the RNA information can be acquired by observing DNA sequence, it has its own meaning. Protein sequencing can be conducted in various way, Edman &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; degradation, &nbsp;Peptide mass fingerprinting, Protease digests, and Mass spectrometry. Through protein sequencing, it can be helpful to sequence target DNA by inferring the protein information.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif"><strong>&nbsp; </strong><u><strong>DNA Sequencing</strong></u></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; Similar with RNA sequencing, the DNA sequencing is an analysis of ordered nucleotide in DNA fragments.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; First sequencing method which is used most broadly in the early stage is &lsquo;Sanger sequencing&rsquo; that is designed by <em>Frederick Sanger</em>. The main feature of this method is the chain termination &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; nucleotide, dideoxynucleotide triphosphates (ddNTPs). The extension of DNA strands is terminated by this nucleotide due to the lack of phosphatidiester bond in 3&rsquo; OH which links one &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; nucleotide and next one. Thus the addition of this molecule generates many DNA fragments in various lengths. Then the fragments are separated by size using electrophoresis and each &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; nucleotide in the end of each fragment can be detected by fluorescence.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; As the methods are keep developed, in these days, the most genome data is analyzed more by pyrosequencing (or 454 sequencing) than Sanger sequencing. It enables faster analysis by using &nbsp; &nbsp; &nbsp; &nbsp; single-nucleotide addition (SNA) method. Due to the limitation in the numbers of nucleotides that can be paused during DNA elongation, the strands can be extended by adding more single &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; nucleotides. And each nucleotide which is linked on the strand adds fluorescence gradually. The increment of its signal can be analyzed in the form of program, which shows the order of &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; lettered nucleotides.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif"><strong>&nbsp; </strong><u><strong>Human Genome Project</strong></u></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; The goal of Human Genome Project is to sequence all existing human chromosome (about 3 billion nucleotides). If the whole genome is determined and analyzed, the every person could be &nbsp; &nbsp; &nbsp; &nbsp; diagnosed with personalized genome information and easy-detection of disease that can occur in future would be possible. And the extreme advance of medical science would be also possible &nbsp; &nbsp; &nbsp; &nbsp; with whole genome information.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; Using those methods described above, many stages of Human Genome Project is completed successfully. With present information, much advanced biomedical research is possible. But still &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; millions of repeat-rich heterochromatin and many significant gaps in DNA strands are not determined.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif"><strong>&nbsp;&nbsp;</strong><u><strong>Conclusion</strong></u></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; In the aspect of DNA sequencing, many methods are gradually developed from 1970s (Sanger sequencing, pyrosequencing, and so on). From those methods the Human Genome Project could &nbsp; &nbsp; &nbsp; be progressed in speeds which would be never possible without it. With the whole genome information in human, the personalized diagnosis will be possible and the cost will keep reduced by &nbsp; &nbsp; &nbsp; newer &nbsp;methods.</span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif"><strong>&nbsp; </strong><u><strong>Reference</strong></u></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp;&nbsp;1. <a href="http://www.nature.com/scitable/topicpage/dna-sequencing-technologies-690">http://www.nature.com/scitable/topicpage/dna-sequencing-technologies-690</a></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; 2. <a href="https://en.wikipedia.org/wiki/Sequencing#RNA_sequencing">https://en.wikipedia.org/wiki/Sequencing#RNA_sequencing</a></span></span></p>

<p><span style="font-size:14px"><span style="font-family:times new roman,times,serif">&nbsp; &nbsp; 3. <a href="http://www.genomenewsnetwork.org/resources/whats_a_genome/Chp2_2.shtml">http://www.genomenewsnetwork.org/resources/whats_a_genome/Chp2_2.shtml</a></span></span></p>