Questions tagged [illumina]
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61
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Does using a microarray chip that matches the chip used in training lead to higher explained variance of a polygenic score?
I'm trying to replicate an existing polygenic score (i.e. test the accuracy in a new sample), and want to know if matching the original study's microarray chip will improve the accuracy (that is, ...
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0
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41
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Does pooled sample genotyping microarray analysis exist?
I want to genotype samples in small batches with a common microarray (e.g., the GSA). However, the cost is very high for small batches.
With a higher sample throughput/volume, per sample cost becomes ...
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30
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How to interpret a GenomeScope plot?
I am working on a new sponge genome and I have produced the genomescope plot from the 21-mer kmer frequencies. I have hard time interpreting the plot. Can someone please help me?
Thank you.
3
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115
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Trimmomatic QC report shows drop in the reads and presence of overrepresented sequences
This question was also asked on Biostars
I am performing a de novo genome assembly using Illumina paired-end short reads, sequenced on a NovaSeq X by our collaborator at UCLA.
At present, I am in the ...
4
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1
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30
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How to get cytoband and gene level copy number from genome wide SNP array copy number data?
I have (human) Illumina genome wide SNP array copy number data. For each SNP genomewide, I have Log R Ratio (LRR) and B Allele Frequency (BAF).
What tool(s) can I use to get the integer copy numbers (...
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2
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49
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paired-end short reads: will one file suffice?
I have a quick question about paired-end short reads. I have multiple genomes that were sequenced with paired-end Illumina NextSeq 200 technology, resulting in two fastq files per sample: ...
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42
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Journal article reference for Illumina's "near monopoly" [closed]
Apologies if the question is out of the scope of the bioinformatics SE. Please feel free to close it if it is the case.
Recently, I have been going into a rabbit hole of papers that discuss the ...
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62
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Can files with different R1 and R2 lengths be trusted?
I received paired end amplicon sequence from a LAB with different lengths for R1 (320) and R2(280). Should I trust this lab to sequence other samples?
Also, I had to do a trimming over the R2 at 220(...
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1
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68
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Singularity and Illumina's Nirvana
I am trying to using Illumina's Nirvana however I can't seem to get it to work despite having the right Singularity path.
I pulled Nirvana down using
...
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35
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illuminaHumanv2.db returning NA for all Illumina probe ID to gene symbol conversion [closed]
This question has been cross-posted on Biostars but has not received any answers yet, so I'm posting it here. I'll update here if it gets answered there.
I have downloaded a miRNA expression dataset ...
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67
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How do I measure the proportion of different bacteria in a sample from a high-throughput sequencer?
[this question is based on a question that was asked on Reddit]
I have sequenced some [mostly cell-free] DNA from a sputum sample on a nanopore sequencing machine, and would like to know what is in it ...
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How much does Nanopore cDNA Sequencing Cost?
[this question is based on a question that was asked on Reddit]
We're interested in doing whole-transcriptome cDNA sequencing of 24 mouse cell lines, and are deciding between Illumina and Nanopore ...
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1
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26
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what does ALT ID DUP refer to when ALT ID for copy number are already specified?
ALT ID CN2, CN3,CN4,CN5 are regions of elevated copy number relative to the reference, Then what does the ID =DUP separately cover? I am new to these analyses. please help
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172
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relation between Illumina sequencing primer and viral sequences
Dealing whith a problematic sequencing run I found this over-represented sequence:
GGAAGAGCACACGTCTGAACTCCAGTCACTAGCTTATCTCGTATGGCGTCTTCTGCTTG
It is clearly relate to the Illumina sequencing primer ...
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2
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2
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177
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Improving prokaryotic assembly with other contig/scaffold-level data?
I have what at first sight appears to be a high-quality MAG (~10 pieces, high completion%) that I built from a hybrid assembly (Illumina + Nanopore data) from a cyanobacterium.
Workflow:
Quality ...
- 881
2
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2
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186
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What should GC coverage bias plot of exome data look like?
I want to see if there is any GC coverage bias in some paired-end Illumina human exome data. Update This is for a variant calling project. I used the ...
- 301
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2
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129
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What is the most accurate approach for de Novo sequencing?
I'm trying to decide between PacBio HiFi or Illumina sequencing platforms for sequencing the genome of aChrysina scarab. We want to identify the color pattern loci and also perform a phylogenetic ...
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26
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Cromwell - controlling core/mem usage, and CallCaching, while running locally?
I'm sitting on a mountain of microarray (.idat files) data, and have been tasked to analyze it. I chose the MoChA pipeline, developed by the Broad Institute. It runs through Cromwell, of which I know ...
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27
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Creating msk file for Illumina Array Analysis CLI Copy number train
recently I'm researching on how to detect CNV from Illumina microarray data. I found that Illumina has Array Analysis CLI software for this task, and I need to train the CN model myself, since the ...
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48
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open source tools for CNV analysis from illumina SNP array
What are the best open source tools to analyse copy number variation using Illumina SNP array data...preferably R based tools, but open to other languages as well.
I'm working with leukemia sample and ...
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32
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Is there a generally accepted method used to impute missing DNA methylation data (probe beta-values)?
I'm looking at DNA methylation (DNAm) data such as TCGA (e.g., BRCA, KIRP, KIRC, etc.). Currently trying to build use my model to predict DNAm age on test sets, but many of the data sets are missing ...
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2
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453
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How to run MD5 check for multiple fastq files in different subdirectories?
I have received Illumina sequencing reads for 100 samples. I have 8 R1.fastq.gz and 8 R2.fastq.gz files for each sample in each ...
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316
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Understand this Kmer plot from Merqury?
The attached figure is generated based on Illumina reads from multiple individuals compared to genome assembly. Looks like there are a lot of kmers are reads only (grey colored). Also, a blue peak (2x ...
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3
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418
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Polishing PacBio or ONT with Illumina
Which tool would be good to polish PacBio or ONT with Illumina?
Thank you in advance
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456
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How to de novo hybrid assemble with Pacbio CCS and Illumina PE reads
I would like to perform de novo genome assembly on a diploid microalgal strain.
I have two datasets:
PacBio CCS/HiFi reads, low coverage.
Illumina PE 2x150 (standard shotgun)
Does anybody have any ...
- 31
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0
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119
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Why is bcl2fastq2 taking so long to calculate stats?
Our lab has been using bcl2fastq v2.20.0.422 to demultiplex RNA-seq data sequenced on an Illumina Novaseq machine on a beefy EC2 instance and we've run into the strange problem: namely that while ...
- 101
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65
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How to perform a meta-analysis using data consisting of paired-end and single-end reads generated from Illumina and Ion Torrent?
So basically I have RNA-seq reads that were generated from Illumina and Ion Torrent platforms for yeast species. I have seen an article where they compared liver cells of a rat that were sequenced ...
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1
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960
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What are some ways to error correct Oxford Nanopore long read sequencing?
I am sequencing long read genomic sequences to assemble MHC region haplotypes in a non model organism using Cas9 Sequencing Kit (SQK-CS9109) using flongle adaptors in the minION from Oxford Nanopore ...
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70
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Which format is the most raw format
I wanted information regarding which format is considered the most raw from an illumina sequencer ?
fasta
fastq
bcl
bam
As per my research it should be bcl but I am not sure.
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81
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polidy VCF file for Canvas somatic-wgs cnv calling
I am trying to run Illumina CANVAS cnv caller for Somatic-WGS. There is an option "--ploidy-vcf" which is mandatory to supply, but don't know what exactly that mean. I had supplied the CNV....
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1
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49
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Modeling number of reads mapped to a gene
I am looking for a probability distribution of a number of reads mapped to a particular gene in metagenomic sequencing (NGS, shotgun, likely illumina).
Naively one could model it via a binomial (or ...
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795
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Error processing run file with bcl2fastq - Unable to open '.../RunInfo.xml' file for reading
I'm attempting to demux a nextseq run which I've successfully done several times in the past on other runs. I uploaded the run from my PC to the server (Ubuntu 18.04.4 LTS) without issue. Then I ran:
<...
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1
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62
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Assembly reads having a copy of their beginning in their tail
I am analyzing the reads for the SARS-CoV-2 assembly with id SRR11140748. Apparently these reads were obtained with parallel sequencing by Illumina and Oxford Nanopore Technologies.
I have found these ...
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1
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46
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Total read count of shotgun affected by few highly abundant sequences
I am building statistical models to analyse output from Illumina shotgun sequencing (HiSeq 4000) on stool samples (but RNA-seq data should behave similarily). The raw counts are a statistical sample ...
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2
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How to demultiplex a mix of single-indexed and dual-indexed samples
The problem
If I have a sample sheet that contains both single-indexed and dual-indexed samples, I can split it up into two sample sheets and then run bcl2fastq on each one. However, when doing this, ...
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0
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933
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What could cause differing counts of R1 and R2 in Paired End Sequencing (RNASEQ)
I recently finished mapping an RNAseq run using STAR2.3.0 and noticed the read1 and read2 counts are different, according to samtools flagstat.
The map% is ~80% but the R1 R2 counts are:
R1=...
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2
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How to predict stop codons in Illumina reads?
I have Illumina MiSeq paired-end reads from 150bp amplicons mapped to my reference genome (> 1000X coverage). These reads have indels that may or may not induce frameshifts. If the indel induces a ...
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2
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1k
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Is there a safe catch-all adapter sequence for trimming?
I would like to trim/mark adapters using trimmomatic or picard MarkIlluminaAdapters from a series of Illumina Paired-End read fastqs. The fastq files may have been done using different kits or ...
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3
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329
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Tools for quality trimming at 5 prime?
I'm looking for a tool that is capable to do quality trimming at 5' end and it is configurable. For example, I can choose the quality trheshold, the read length, etc. Any recommendations?
I'm ...
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4
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2
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3k
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"Sequence Duplication Levels" module still fails after pre-processing Illumina data
I want to ask about why the sequence duplication levels are high after I trimmed by using Trimmomatic? I am using the following Trimmomatic operations: ...
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464
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How to align output of grep --color=always? (To QC fasta/fastq files)
Grepping out short sequences from a fasta or fastq file is a really useful way to look at sequencing data. Using the option --color=always makes this even more ...
- 3,141
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Why are there more barcodes than GEMs in 10X chromium data?
Question: Why are there more barcodes than GEMs in 10X chromium data?
Introduction
I have several 10X genomics chromium libraries made with the de novo assembly/genome protocol. The 10X chromium ...
- 3,141
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What is the index fastq file (sample_I*.fastq.gz) generated when demultiplexing Illumina paired-end runs?
What is the index fastq file that comes with some Illumina sequencing datasets? (The samplename_I*.fastq.gz file.)
For example, I recently received some 10X ...
- 3,141
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2
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2k
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What is the correct way to map Hi-C data with bwa mem?
Library Prep
I have a Hi-C library prepped using an enzyme that cuts at GATC, so it leaves GATCGATC as the junction sequences. ...
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1
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How many reads do I need for hybrid assembly
I have Illumina and PacBio reads and I would like to use dbg2olc for hybrid assembly.
Part of dbg2olc is SelectLongestReads which select reads that sum to ...
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80
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Genotyping with Illumina HumanOmni1-Quad before whole genome sequencing
I read a paper about (whole genome sequencing analysis of 100 Southeast Asian Malays. It says "Prior to library preparation, each sample was genotyped on the Illumina HumanOmni1-Quad as an initial ...
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785
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Relationship between sequencing lane and ngs dataset
I am fairly new to NGS data analysis and I am struggling to understand the exact relationship between a sequencing lane and an NGS dataset. I should add I don't work in the lab, I only do ...
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Why do NEBNext indexing primers have sequence between the p5 oligo and index?
In a previous post I asked Why do NEB adapters have non-complementary sequence?
Since then, I realized that there is some other sequence in the p5 indexing primer, as well as in the p7 indexing ...
- 3,141
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153
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Viral Metagenomics
I am analyzing viral metagenomics data (Illumina Miseq) for the first time. I have used Ray (reference below) for de novo viral genome assembly before but I haven't done metagenomics analysis before.
...
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418
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Get gene names corresponding to CPG probes
I have downloaded KIRC Methylation data (450K) using TCGA toolbox. The beta values given are with reference to CPG probes. Is there any package or function in R through which I can get the gene names ...
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