<p>Sequencing technology<br />Sequencing companies<br /><br /><br /><br /><span style="font-size:24px"br /><strongbr />DNA Sequencing<br /strong><br /span>&nbsp;</p>

<p>What is sequencing?In genetics and biochemistry, <span style="font-size:20px"strong>sequencing</strong>What is means to determine the primary structure (or primary sequence) of an unbranched biopolymer. Sequencing?results in a symbolic linear depiction known as a </strong>sequence</spanstrong>which succinctly summarizes much of the atomic-level structure of the sequenced molecule.</p>

<p>&nbsp;<span style="font-size:14px"/p>DNA sequencing is the process of determining the nucleotide order of a given DNA fragment. Thus far, most DNA sequencing has been performed using the chain termination method developed by Frederick Sanger. This technique uses sequence-specific termination of a DNA synthesis reaction using modified nucleotide substrates. However, new sequencing technologies such as Pyrosequencing are gaining an increasing share of the sequencing market. More genome data is being produced by pyrosequencing than Sanger DNA sequencing these days. Pyrosequencing has enabled rapid genome sequencing. Bacterial genome can be sequenced in a single run with several X coverage with this technique. This technique was also used to sequence the genome of James Watson recently. </spanp>&nbsp;</p>

<ph2>DNA sequencing<span style="font-size:20px"/h2> <strongp>Why DNA sequencing is important?the process of determining the nucleotide order of a given DNA fragment. Thus far, most DNA sequencing has been performed using the chain termination method developed by Frederick Sanger. This technique uses sequence-specific termination of a DNA synthesis reaction using modified nucleotide substrates. However, new sequencing technologies such as Pyrosequencing are gaining an increasing share of the sequencing market. More genome data is being produced by pyrosequencing than Sanger DNA sequencing these days. Pyrosequencing has enabled rapid genome sequencing. Bacterial genome can be sequenced in a single run with several X coverage with this technique. This technique was also used to sequence the genome of James Watson recently.</strongp> </spanp>The sequence of DNA encodes the necessary information for living things to survive and reproduce. Determining the sequence is therefore useful in &#39;pure&#39; research into why and how organisms live, as well as in applied subjects. Because of the key nature of DNA to living things, knowledge of DNA sequence may come in useful in practically any biological research. For example, in medicine it can be used to identify, diagnose and potentially develop treatments for genetic diseases. Similarly, research into pathogens may lead to treatments for contagious diseases. Biotechnology is a burgeoning discipline, with the potential for many useful products and services.</p>

<ph3>Sanger sequencing</h3> <div class="thumb tright"><div class="thumbinner" style="WIDTH: 162px"><img alt="Part of a radioactively labelled sequencing gel" class="thumbimage" src="http://upload.wikimedia.org/wikipedia/commons/c/cb/Sequencing.jpg" style="height:332px; width:160px" /><div class="thumbcaption"><span div class="magnify" style="fontFLOAT: right"><img alt="" src="http://en.wikipedia.org/skins-1.5/common/images/magnify-sizeclip.png" style="height:11px; width:14px15px"/></div>Genome Part of a radioactively labelled sequencing gel</div></div></div> <p>In chain terminator sequencing (Sanger sequencing), extension is figuring out initiated at a specific site on the order of template DNA nucleotides, or basesby using a short oligonucleotide &#39;primer&#39; complementary to the template at that region. When you read The oligonucleotide primer is extended using a sentenceDNA polymerase, an enzyme that replicates DNA. Included with the meaning is not just in primer and DNA polymerase are the sequence four deoxynucleotide bases (DNA building blocks), along with a low concentration of a chain terminating nucleotide (most commonly a <strong>di-</strong>deoxynucleotide). Limited incorporation of the letters. It is also in chain terminating nucleotide by the words those letters make and DNA polymerase results in the grammar a series of the languagerelated DNA fragments that are terminated only at positions where that particular nucleotide is used. SimilarlyThe fragments are then size-separated by electrophoresis in a slab polyacrylamide gel, the human genome is or more than just its sequencecommonly now, in a narrow glass tube (capillary) filled with a viscous polymer. Sequencing </p> <div class="thumb tright"><div class="thumbinner" style="WIDTH: 182px"><img alt="View of the genome is start of an important step towards understanding itexample dye-terminator read (click to expand)" class="thumbimage" src="http://upload.wikimedia.org/wikipedia/commons/thumb/4/44/Sanger_sequencing_read_display.gif/180px-Sanger_sequencing_read_display.gif" style="height:42px; width:180px" /><div class="thumbcaption"><div class="magnify" style="FLOAT: right"><img alt="" src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip. Scientists also hope that being able png" style="height:11px; width:15px" /></div>View of the start of an example dye-terminator read (click to expand)</div></div></div> <p>An alternative to study the entire genome sequence will help them understand how labelling of the genome works&mdash;how genes work together primer is to direct label the growthterminators instead, development and maintenance commonly called &#39;dye terminator sequencing&#39;. The major advantage of an entire organism. Finallythis approach is the complete sequencing set can be performed in a single reaction, genes account for less rather than 25 percent the four needed with the labeled-primer approach. This is accomplished by labelling each of the DNA in the genomedideoxynucleotide chain-terminators with a separate fluorescent dye, which fluoresces at a different wavelength. This method is easier and so knowing quicker than the entire genome sequence will help scientists study dye primer approach, but may produce more uneven data peaks (different heights), due to a template dependent difference in the parts incorporation of the genome outside large dye chain-terminators. This problem has been significantly reduced with the genesintroduction of new enzymes and dyes that minimize incorporation variability. </p> <p>This includes method is now used for the regulatory regions vast majority of sequencing reactions as it is both simpler and cheaper. The major reason for this is that control how genes are turned on an offthe primers do not have to be separately labelled (which can be a significant expense for a single-use custom primer), as well as long stretches although this is less of junk DNAa concern with frequently used &#39;universal&#39; primers.</span></p>

<ph3>Pyrosequencing<span style="font-size:20px"/h3> <strongp>How Pyrosequencing, which was originally developed by Mostafa Ronaghi, has been commercialized by Biotage (for low throughput sequencing ) and 454 Life Sciences (for high-throughput sequencing). The latter platform sequences roughly 100 megabases in a 7-hour run with a single machine. In the array-based method (commercialized by 454 Life Sciences), single-stranded DNA is operated?</strong></span>annealed to beads and amplified via emPCR. These DNA-bound beads are then placed into wells on a fiber-optic chip along with enzymes which produce light in the presence of ATP. When free nucleotides are washed over this chip, light is produced as ATP is generated when nucleotides join with their complementary base pairs. Addition of one (or more) nucleotide(s) results in a reaction that generates a light signal that is recorded by the CCD camera in the instrument. The signal strength is proportional to the number of nucleotides, for example, homopolymer stretches, incorporated in a single nucleotide flow. [1]</p>

<ph2>RNA sequencing</h2> <span style="font-size:14px"p>The whole genome canRNA is less stable in the cell, and also more prone to nuclease attack experimentally. As RNA is generated by transcription from DNA, the information is already present in the cell&#39;t be sequenced all at once because available methods of s DNA sequencing can only handle short stretches of . However, it is sometimes desirable to sequence RNA molecules. In particular, in Eukaryotes RNA molecules are not necessarily co-linear with their DNA at a timetemplate, as introns are excised. So insteadTo sequence RNA, scientists must break the genome into small pieces, sequence usual method is first to reverse transcribe the pieces, and sample to generate DNA fragments. This can then reassemble them in the proper orderbe sequenced as described above. An automatic sequencing machine spits out what genome scientists call </p> <p>&quotnbsp;raw&quot; sequence. In raw </p> <h2>Protein sequencing</h2> <p>Methods for performing protein sequencing include:</p> <ul> <li>Edman degradation</li> <li>Peptide mass fingerprinting</li> <li>Mass spectrometry</li> <li>Protease digests</li></ul> <p>If the gene encoding the protein can be identified it is currently much easier to sequence, the reads or short DNA sequences are all jumbled togetherand infer the protein sequence. The process Determining part of a protein&#39;s amino-acid sequence (often one end) by one of transforming the fragmented rough draft into above methods may be sufficient to enable the identification of a long, continuous final product without breaks or errors is called finishing. Finishing often takes longer than clone carrying the sequencing itselfgene.</span></p>

<ph2>Polysaccharide sequencing<span style="font-size:20px"/h2> <strongp>Which kinds Though polysaccharides are also biopolymers, it is not so common to talk of &#39;sequencing techniques &#39; a polysaccharide, for several reasons. Although many polysaccharides are linear, many have branches. Many different units (individual monosaccharides) can be used, and bonded in different ways. However, the main theoretical reason is that whereas the other polymers listed here are available?primarily generated in a &#39;template-dependent&#39; manner by one processive enzyme, each individual join in a polysaccharide may be formed by a different enzyme. In many cases the assembly is not uniquely specified; depending on which enzyme acts, one of several different units may be incorporated. This can lead to a family of similar molecules being formed. This is particularly true for plant polysaccharides. Methods for the structure determination of oligosaccharides and polysaccharides include NMR spectroscopy and methylation analysis</strongsup>[1]</spansup>.</p>

<p><span style="font-size:14px">To facilitate their full genome sequencing initiatives, &ldquo;Illumina&rdquo; licensed nanopore sequencing technology from Oxford Nanopore Technologies. Illumina sequencing system based on reversible terminators for sequence determination. It is an approach that generates several billion bases of accurate nucleotide sequence per experiment at low cost. Single molecules of DNA are attached to a flat surface, amplified in situ and used as templates for synthetic sequencing with fluorescent reversible terminator deoxyribonucleotides. Another possible way to accomplish cost-effective high-throughput sequencing is by utilizing fluorophore technology. Pacific Biosciences is currently using this approach in their SMRT (Single Molecule Real Time) DNA sequencing technology. SMRT sequencing is a harnesses the natural process of DNA replication and enables real-time observation of DNA synthesis by using phosphorlinked nucleotides.</spanh2>See also</ph2>

<h3ul>&nbsp; <li>Genetic code</li> <li>Sequence motif</li> <li>[http://sequenceome.org Sequenceome.org]</li> <li>[http://glycome.net Glycome.net]</li></h3ul>

<p><span stylea id="font-size:20pxReferences" name="><strong>References</strong"></spana></p>

<ph2>&nbsp;References</ph2>

<li><span stylestrong><a href="font-sizehttp:14px">N/A. (2008). Accurate Whole Human Genome Sequencing using Reversible Terminator Chemistry/en. <em>Naturewikipedia.<org/em> <em>456<wiki/emSequencing#_ref-0" title="">(7218): 53&ndash;59.^</spana></listrong> <li><span stylea class="external text" href="font-sizehttp:14px">Xiaoge, G//www., Kevin, Lstenutz., Karen, O., Jenny Zeu/sop" rel="nofollow" title="http://www., Sandeep Sstenutz. D., &amp; Sue J.R. (2015). SMRT Sequencing for Parallel Analysis of Multiple Targets and Accurate SNP Phasing. <em>G3<eu/emsop">. g3.115.023317A practical guide to structural analysis of carbohydrates</spana></li>

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