Next Generation Sequencing (NGS)

Trace the historical background of next generation sequencing (NGS), from early DNA sequencing milestones to the first commercial NGS platforms, and compare it with Sanger sequencing.

Next generation sequencing enables massively parallel, ultra-high throughput genome and targeted region sequencing, letting researchers determine nucleotide order in days or hours.

Next generation sequencing applies clonal amplification by PCR, sequencing by synthesis, and massively parallel reads, then maps data to reference genomes through bioinformatics.

Compare Sanger sequencing and next generation sequencing, highlighting differences in sequencing volume, data throughput, sensitivity, and speed, with next generation sequencing offering high throughput and rapid, cheap analysis.

Isolate nucleic acids from diverse samples, preserve integrity at low temperature, then quality control with gel electrophoresis and NanoDrop, and prepare libraries with reverse transcription and PCR amplification for sequencing.

Fragment purified DNA, repair ends, add an adenine overhang, and ligate adapters with thymine overhangs to form a sequencing library for multiplexed, second-generation sequencing.

Explain PCR amplification in next generation sequencing, covering emulsion PCR on bead-bound DNA with adapters and bridge PCR on flow cells to generate amplified, sequence-ready DNA.

Explore pyrosequencing as a sequencing-by-synthesis approach in next generation sequencing, using emulsion PCR, DNA polymerase, and light emitted by luciferase to detect nucleotide incorporation via pyrophosphate release.

The SOLiD sequencing by ligation uses emulsion PCR to amplify DNA on beads attached to a solid phase, then detects fluorescent dye labeled di-nucleotide probes to read sequences.

Ion Torrent semiconductor sequencing detects hydrogen ions released during DNA polymerization to perform sequencing by synthesis, leveraging emulsion PCR and hydrogen detection instead of fluorescence.

Illumina reversible terminator sequencing uses sequencing by synthesis with fluorescent, reversible terminator nucleotides, imaging after each incorporation and cleavage, and distinguishes blocked versus unblocked terminators.

Explore next generation sequencing as short read sequencing with paired-end and single-end reads. Use 200–800 bp to double reads and improve alignment, enabling insertion–deletion detection, small RNA and ChIP sequencing.

Explore data analysis as the post-processing stage of next generation sequencing, including quality control with fastqc, pre-processing, mapping or de novo assembly, and variant analysis with visualization.

Identify key considerations when selecting sequencing strategy, from research questions and sample type to extraction methods, library preparation, read length, genome vs transcriptome, multiplexing, and bioinformatics tools.

Explore the strengths of next generation sequencing, including fast, highly sensitive genome-wide detection of substitutions, deletions, insertions, duplications, and copy number changes, with low DNA input and rapid, affordable results.

Explore limitations of next generation sequencing, including unknown reference data, uncertain clinical significance of abnormalities, PCR biases, GC content effects, data deluge, and limited computational resources for analysis.

Explore applications of next generation sequencing, including whole genome sequencing, targeted gene panels, ChIP-seq, and transcriptome and metagenomic sequencing, to support outbreak management, antimicrobial resistance surveillance, and pathogen discovery.

Explore third and fourth generation long read sequencing, including PCR-free, single-molecule methods with real-time nucleotide incorporation and nanopore sequencing, highlighting biases, cost, and data availability.

Explore the limits of short-read sequencing, including 35–600 base reads and fragmented genome assemblies. Learn how long-read sequencing from Pacific Bioscience and Oxford Nanopore offers solutions.

Explain long read sequencing, aka third generation sequencing, and how sequencing single molecules without amplification overcomes short read limits to reveal long reads for structural variants, repeats, and full-length transcripts.

Discover the benefits of long read sequencing, including real-time clinical insights for pathogen detection and antimicrobial resistance, plus scalable portable platforms for de novo genome assembly.

Explore long read sequencing technologies, including PacBio and Oxford Nanopore, and learn how their approaches generate longer, more accurate reads for complex genome assemblies and structural variation detection.

Explore PacBio sequencing, which uses single molecule real time sequencing to deliver long, high accuracy reads. These reads enable genome assemblies, structural variation detection, and full length transcriptomics.

Discover PacBio sequencing features, including single-molecule real-time sequencing that eliminates amplification biases and offers long reads. Achieve hi fi accuracy over 99.9% with real-time data acquisition.

Explore PacBio SMRT sequencing, from high molecular weight DNA extraction and fragmentation to smart bell template preparation and circular consensus sequencing, with real-time sequencing in smart cells.

Learn how PacBio SMRT sequencing uses fluorescently labeled nucleotides detected by high-speed cameras to read DNA in circular consensus sequencing, delivering long, high-fidelity reads with over 99.9% accuracy.

PacBio HiFi sequencing delivers accuracy and long reads but faces computational cost and data processing needs, requiring specialized instruments and trained experts, with lower throughput than short-read platforms, impacting scalability.

Explore Oxford Nanopore Technologies (ONT), a long-read sequencing approach that analyzes signals through nanopores to sequence DNA or RNA in real time and compare short read with long read sequencing.

Explore Oxford Nanopore Technologies' real-time, direct sequencing of DNA and RNA without amplification or reverse transcription, highlighting ultra long reads over 2 million base pairs and portable Promethean platforms.

Explore the ONT sequencing process from sample prep and adapters to nanopore flow cells, motor proteins, and real-time signal detection for base calling and analysis without amplification.

Explore the challenges of nanopore sequencing, including raw read accuracy, signal noise, and base-calling errors. Evaluate data-analysis requirements, cost of platforms, and sequencing speed constraints.

Compare short-read and long-read sequencing, highlighting read length, accuracy, throughput, cost, portability, and applications. Explore PacBio, ONT, and Illumina for structural variation, epigenetic detection, and assembly.