Introduction to Next Generation Sequencing

the oxy ribonucleic acid DNA wire scientists and doctors so interested in its wonders well DNA is like an encyclopedia the words inside are composed of only four letters a adenine g guanine c cytosine and T chiming when scientists examine DNA they carefully read each and every word inside this complicated encyclopedia when the words finally begin to make sense marvelous things can start to happen but how do we retrieve these words or DNA sequences analyzing DNA sequences have aided in several scientific fields since the 1900s from Sanger sequencing to applied Biosystems to the genome analyzer scientists clearly have an insatiable hunger for finding the next best technology to accurately sequence large portions of DNA next generation sequencing also known as NGS has fundamentally changed the scientific world it is important to note that the cost regarding next-generation sequencing are significantly lower than in any other point in DNA sequencing history Illumina is a largely successful biotechnology company that plays a large role in next-generation sequencing they are four steps that briefly explain the complicated process regarding this version of DNA sequencing library preparation cluster generation sequencing and data analysis let's start from the beginning the first phase of this process is library preparation essentially a DNA sample is broken down and specialized adapters are glued to the two sides of the fragmented DNA these two steps are done simultaneously which helps immensely with the proficiency of the stage the new DNA fragments are then led to polymerase chain reaction or PCR amplification they are then gel purified the second phase is clustered generation a DNA library is carefully placed into a flow cell DNA fragments attached to the top of the slow cell this is a complicated step where the flow cell contains ala ghosts that complement the incoming library adapters attached to the DNA fragrance this step is not complete until every DNA fragment goes through a bridge amplification cycle the second phase is tedious but it is extremely important for entry into the third phase the third phase is sequencing nucleotides are added and Illumina technology is able to identify single basis as they combine into each DNA strand the nucleotides in this step are very special because they are fluorescently labeled this helps the scientist carefully analyze each cluster where the first spaces within each of the four clusters can be visualized due to fluorescent lights the final phase is data analysis once the scientists are able to visualize the various DNA sequences they are sequentially aligned using a reference DNA sequence also known as a reference genome a reference genome is a man-made DNA sequence that expresses a specific species set of genes this phase can only be done using an advanced bioinformatics program this program helps distinguish any variances between the aligned reads and their reference DNA sequence computational methods are then used to aid in the creation of visual models such as phylogenetic trees overall next-generation sequencing has become a popular process that can aid in various scientific fields millions of DNA sequences can quickly be processed at astonishingly low rates this is only the beginning of a new scientific era

Channel: George Mason Bioinformatics

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Keywords: NGS, Next Generation Sequencing

Id: ToKUGz_YhC4

Length: 4min 0sec (240 seconds)

Published: Thu Sep 07 2017