1. DNA Sequencing

2. DNA Sequencing The first DNA sequences were obtained in the early1970s . Sequence individual genes larger genetic regions (i.e. clusters of genes oroperons) full chromosomes or entire genomes. Useful in biotechnology research and discovery,diagnostics, and forensics. 3. Next-Generation Of SequencingNext-Generation Of Sequencing Massive parallel Sequencing second-generation sequencing 4. INTRODUCTION Imp role in the advancement of molecular biology The fast and low-cost sequencing approachesprovide new opportunities for sequencing in variousapplications Over the past few years, we have seen next-gentechnologies being applied in a variety of contexts 5. CURRENT NEXT-GENERATION SEQUENCINGPLATFORMS 6. The three dominate commercial platforms are the Roche 454 Genome Sequencer, the Illumina Genome Analyzer, and the Life Technologies SOLiD System developed at the end of 1990s and commercializedaround 2005. 7. THE ROCHE 454 8. Emulsion PCR 9. LIMITATIONS the per-base cost of sequencing is much higherthan that of other next generation platforms unsuitable for sequencing targeted fragments 10. ADVANTAGES generate more than 1,000,000 individual reads With length of 400 bases per 10 h instrument run best choice for certain applications where longread-lengths required 11. THE ILLUMINA (SOLEXA) 12. THE LIFE TECHNOLOGIES SOLID SYSTEM 13. APPLICATIONS reduced costs and increased the throughput, ascompared to Sanger sequencing.1. Whole-genome sequencing can identify single nucleotide variations and structuralvariations in the genome, many of which may have a causativerole in disease.2. RNA-Seq The transcriptome represents the complete set of transcripts ina cell gives information on the functional elements of the genome 14. 3. ChIP-Seq antibodies select proteins and thereby enrich DNAfragments bound to it, which are then sequenced4. Exome Sequencing protein-coding regions (exome) constitute less than 2% ofthe entire genome But it will miss mutations in non-coding regions of thegenome (introns) 15. 5. Microbiome Sequencing6. Ribonomics RNA-binding proteins are involved in processing of RNAand affect regulation of gene expression.7. Epigenomics Epigenetic modifications such as DNA methylation andcovalent modifications of histone proteins can be mapped 16. LIMITATIONS OF NEXT-GENERATIONSEQUENCING Shorter read lengthsIt better serves as a genome re-sequencing tool. Repetitive DNA Data VolumeLarge volumes of data , time consuming and expensive 17. Despite these limitations, it is obvious thatNGS has revolutionized the fields of researchand medicine