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"Data and information management is..."
  • Data and information management is slowly moving out of infancy in genomics science…. at the toddler stage…


  • The Good news
    • Some data formats are being accepted widely


  • The Bad news
    • Still many competing standards in some areas
    • Interoperability of data standards is almost non-existent
    • Governance is questionable


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Data Format Types
  • Raw Sequence Data e.g. fasta



  • Aligned data e.g. BAM



  • Processed data e.g. BED
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Interpreting raw data
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HTseq Raw Data Format
  • fasta (Sanger)
  • csfasta (SOLiD)
  • fastq (Solexa)
  • sff (454)
  • …. And about 30 other file formats


  • http://emboss.sourceforge.net/docs/themes/SequenceFormats.html



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SOLiD Color Space
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(cs)Fasta/(cs)Fastq
  • FASTA
    • Header line “>”
    • Sequence
  • FASTQ
    • Add QVs encoded as single byte ASCII codes
  • Most aligners accept FASTA/Q as input
  • Issue: data is volumous (2 bytes per base for FASTQ)
  • Do PHRED scaled values provide the most information?
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454 output formats
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Illumina output formats
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"ASCII value for h"
  • ASCII value for h= 103
  • Quality of Base A at the position 1 = 103- 64
  • 103- 64 = 39
  • Where 39 is the phred score
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NGS QC Toolkit & FastQC
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