The High-Throughput Technologies Speeding Up Biomedical Science

Next-Generation Sequencing Sanger-sequencing based approaches are also called firstgeneration techniques. NGS platforms are the second generationof sequencing technology. Third-generation sequencing technologies involve sequencing long nucleic acid chains. This technology has advantages over previous methods: • Ability to quickly assess methylation sites • Devices can be portable and lower cost • But is currently undermined by a high error rate. T Next-generation sequencing (NGS) techniques have greatly enhanced the output of genomic research. Sanger sequencing, which dominated the field before NGS, took 13 years to sequence the first human genome. NGS can do it in just over 5 hours. An overview of NGS Biological and biomedical research used to be a field anchored down by the weight of timeconsuming manual tasks. Involved and laborious wet-lab processes slowed output to a crawl. But now, high-throughput technologies have ramped up the speed of science. In this infographic, we take a deep dive into how these technologies have changed the game. Sample/genome Fragmentation End repair & adapter ligation Clonal amplification by emulsion PCR Sequencing by ligation Pyrosequencing PPi ATP-Sulfurylase ATP Luciferase Ligase Proton detection sequencing Reversible terminator sequencing Clonal amplification by bridge PCR Cluster generation A B DNA polymerase Time Intensity DNA polymerase DNA ligase G A C A T A A C A C T A C T G T G A C A T A A C A C T A A A T T C T G T DNA polymerase H+ H+ H+ In short-read NGS, genetic material (DNA or RNA) is fragmented and oligonucleotides of known sequence are bolted on through a step called adapter ligation. This enables the fragments to interact with and be identified by the sequencing system. Sequencing by ligation doesn’t utilize DNA polymerase to create a second strand. DNA ligase’s sensitivity to basepairing mismatches is exploited instead. The fluorescence produced is used to determine the target sequence. Digital images taken after each reaction are then used for analysis. Pyrosequencing detects the generation of pyrophosphates and light release to determine whether a specific base has been incorporated in a DNA chain. Proton detection sequencing counts the hydrogen ions that are released when DNA polymerizes. pH changes are detected by semiconductorbased sensor chips and are then converted to digital readouts. Reversible terminator sequencing utilizes ‘’bridgeamplification’’. During synthesis, fragments bind to oligonucleotides on the flow cell, creating a bridge from one side of the sequence to the other, which is then amplified. The fluorescently labeled nucleotides that are added during this process are detected using direct imaging.