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lecture_notes:04-20-2011

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lecture_notes:04-20-2011 [2011/04/21 05:07]
svohr created
lecture_notes:04-20-2011 [2015/09/06 06:32] (current)
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 ====== New Hardware ====== ====== New Hardware ======
-As of April 20, two new machines have been added to [[computer_resources:​campusrocks|campusrocks]],​ each with 48 cores and 192 GB of RAM. These machines appear to be good candidates for running the more memory intensive assemblers ([[bioinformatic_tools:​soapdenovo|SOAPdenovo]],​ [[bioinformatic_tools:​allpaths|ALLPATHS]],​ and [[bioinformatic_tools:​abyss|ABySS]]).+As of April 20, two new machines have been added to [[archive:computer_resources:​campusrocks|campusrocks]],​ each with 48 cores and 192 GB of RAM. These machines appear to be good candidates for running the more memory intensive assemblers ([[archive:bioinformatic_tools:​soapdenovo|SOAPdenovo]],​ [[archive:bioinformatic_tools:​allpaths|ALLPATHS]],​ and [[archive:bioinformatic_tools:​abyss|ABySS]]).
  
 ====== High-Frequency K-mers ====== ====== High-Frequency K-mers ======
-We noticed a discrepancy in the total k-mer counts found using the histogram and the total number of k-mers from the ''​jellyfish stats''​ command. It turned out that there were k-mer counts the were  much higher than the 500 and later 5,000 cut off we applied using the ''​jellyfish histo''​ command. For the first illumina run the maximum count found for a 22-mer was 23,661,844, and in run 2 the maximum count for a 22-mer was 6,090,098. The k-mers with extremely high counts are likely the result of contamination or an artifact from the library preparation. We need to examine these k-mers to find where they came from. One possible solution is to run [[bioinformatic_tools:​seqprep|SeqPrep]] before counting k-mers to remove adapter sequences from +We noticed a discrepancy in the total k-mer counts found using the histogram and the total number of k-mers from the ''​jellyfish stats''​ command. It turned out that there were k-mer counts the were  much higher than the 500 and later 5,000 cut off we applied using the ''​jellyfish histo''​ command. For the first illumina run the maximum count found for a 22-mer was 23,661,844, and in run 2 the maximum count for a 22-mer was 6,090,098. The k-mers with extremely high counts are likely the result of contamination or an artifact from the library preparation. We need to examine these k-mers to find where they came from. One possible solution is to run [[archive:bioinformatic_tools:​seqprep|SeqPrep]] before counting k-mers to remove adapter sequences from 
 the reads. ​ the reads. ​
  
lecture_notes/04-20-2011.1303362473.txt.gz · Last modified: 2011/04/21 05:07 by svohr