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--- archive:bioinformatic_tools:soapdenovo [2010/05/16 21:30]
galt
+++ archive:bioinformatic_tools:soapdenovo [2015/07/28 06:26] (current)
ceisenhart ↷ Page moved from bioinformatic_tools:soapdenovo to archive:bioinformatic_tools:soapdenovo
@@ Line 25: / Line 25: @@
 Downloaded the binaries for SOAPdenovo and [[http://soap.genomics.org.cn/about.html#resource2|GapCloser]]. I copied these binaries to the /bin folder since there are only two, and they at least correctly display a help message when you run them without arguments.
+==== Method ====
+The method for SOAPdenovo is described in the paper [[http://genome.cshlp.org/content/20/2/265.full|"De novo assembly of human genomes with massively parallel short read sequencing"]] by Li et al.
+=== Short Read Data ===
+Fragment and paired-end libraries are sequenced using various insert sizes. They used read lengths from 35 to 75 bp and insert sizes of 140 bp, 440 bp, 2.6 kb, 6 kb, and 9.6 kb.
+Basic error correction was performed on the reads using K-mer counting to reduce the memory usage when constructing the de Bruijn graph. This was done by identifying low frequency (occurring <3 times) 17-mers and correcting these K-mers to the candidate with the highest frequency.
+=== De Bruijn Graph ===
+The next step is to build the de Bruijn graph to represent overlap of k-mers. 25-mers were used in their assembly.
+Only the single-end and paired-end reads with short insert sizes (<1 kb) were used in the graph due the high probability of chimeric reads in the long-insert pairs from the circularizing and fragmentation process. Further error correction is done using the de Bruijn graph.
+    * Clip tips (low coverage paths that lead to dead ends)
+    * Remove low coverage links
+    * Resolve tiny repeats greater than K, but less than the read lengths.
+    * Merge bubbles (paths with the same start and end). These can represent an error or a true polymorphism.
 ==== Quirks ====
@@ Line 38: / Line 55: @@
 Perhaps it just won't take the fasta input by itself.
 It might work if you include a qual file with your fasta.
+==== Using SOAPdenovo ====
+SOAPdenovo has three executables each tuned for a different range of k-mer sizes (SOAPdenovo-31mer, SOAPdenovo-63mer, SOAPdenovo-127mer). For example, ''SOAPdenovo-31mer'' works best on k-mer sizes up to and including 31. For larger k-mers than 31 and lower than 64, use ''SOAPdenovo-63mer''.
+SOAPdenovo requires a configuration file that describes the libraries that will be used in the assembly. A library entry is required for each read file or pair of read files in the case of paired-end reads. Here is an example of the 5 library entries for 1 lane of run1.
+<code>
+[LIB]
+#average insert size
+avg_ins=150
+#if sequence needs to be reversed
+reverse_seq=0
+#in which part(s) the reads are used
+asm_flags=3
+#in which order the reads are used while scaffolding
+rank=1
+#fastq file for read 1
+q1=/campusdata/BME235/data/slug/clean/run1_seqprep_quake/s_1_1_qseq_seqprep.cor.fastq.gz
+#fastq file for read 2 always follows fastq file for read 1
+q2=/campusdata/BME235/data/slug/clean/run1_seqprep_quake/s_1_2_qseq_seqprep.cor.fastq.gz
+[LIB]
+reverse_seq=0
+asm_flags=3
+rank=1
+q=/campusdata/BME235/data/slug/clean/run1_seqprep_quake/s_1_1_qseq_seqprep.cor_single.fastq.gz
+[LIB]
+reverse_seq=1
+asm_flags=3
+rank=1
+q=/campusdata/BME235/data/slug/clean/run1_seqprep_quake/s_1_2_qseq_seqprep.cor_single.fastq.gz
+[LIB]
+reverse_seq=0
+asm_flags=3
+rank=1
+q=/campusdata/BME235/data/slug/clean/run1_seqprep_quake/s_1_merged_qseq_seqprep.cor.fastq.gz
+</code>

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