Questions tagged [fastq]

FASTQ is a file format use to store short reads and their quality values

Filter by
Sorted by
Tagged with
0
votes
1answer
46 views

Converting Fastq files to Fasta files on Ubuntu

I am new to bioinformatics and programming. I tried to convert my fastq files to fasta file, but got this. What could be wrong? ...
0
votes
1answer
75 views

Converting fastq to fastq.gz on windows

I downloaded some of my data in fastq format instead of fastq.gz. I want to upload my data on a server now. I was wondering if there is a way to convert my fastq files to fastq.gz on windows (I read ...
0
votes
1answer
12 views

Impact of merging ChIP-seq runs of the same sample on PCR duplicates identification?

I'd like to a follow up question to this question related to merging fastq files for ChIP-seq. Let's assume we have one sample library that is re-sequenced two or three times in order to achieve a ...
1
vote
1answer
52 views

How to convert CRAM file with 10x data in three fastq files

10x Genomics data are stored in three FASTQ files, besides the standard R1 and R2 reads, there is also a I1 file with some metadata. Sometimes however they are shipped in a single bam/cram file (e.g. ...
1
vote
3answers
71 views

Finding smaller sequences from within larger sequences

I am currently working with fastq files which have hundreds of thousands of lines of text. However, not all of them are sequences I am interested in. My sequences are in one line and have a fixed ...
0
votes
0answers
57 views

Could one Align a FastQ data to a reference genome

I need help with the following question : Given a FastQ data what can we do directly with it ? Assess it for Quality control Align it to a reference genome Call variants Assemble's genome My Thoughts ...
1
vote
2answers
64 views

Get frequency of index sequences of fastq file

I recently did some sequencing on a MiniSeq and unexpectedly the Undetermined_S0_L001_R1_001.fastq.gz file contained quite a lot of data (about 40% of total). I ...
1
vote
1answer
184 views

How to convert txt.gz into fastq.gz?

I'm a newbie to bioinfo. I'm trying to use galaxy.networkanalyst.ca for the analysis of RNA-Seq data and for that I need to convert txt.gz files into fastq.gz files. Link: GSM4273445 is one sample ...
0
votes
1answer
36 views

Demultiplexing FASTQ file without index information

I am trying to understand how data that was uploaded to SRA (https://www.ncbi.nlm.nih.gov/sra?LinkName=biosample_sra&from_uid=4510743) can be analyzed with the assumption that the FASTQ file ...
4
votes
1answer
53 views

Telling grep to treat N as [ATCG]

Okay so I'm using grep to try and get a preview of some trimming operations that are not going as expected.. Lets say that my sequence in the FastQ file is: ATNGCNATCG What I want to do is.. ...
1
vote
2answers
106 views

Fastq: how can I check if they are from DNA or RNAseq data?

I have (gave me) Illumina fastq files, which I want to use for variant calling, and I do not know if they are DNAseq or RNAseq data. How can I check this? I do not have any report or who to ask. Many ...
0
votes
0answers
40 views

How do you determine the strandedness of a RNAseq dataset? [duplicate]

How do you verify if a RNAseq dataset is unstranded, stranded or revesely stranded from a fastq file?
4
votes
1answer
54 views

Find pattern that is present twice and allow <=2 mismatches on each

I have a fastq file of 400,000 reads (so speed is important). In the sequences there are barcodes integrated that should be present twice. Given a barcode, I want to find the sequences that have the ...
1
vote
1answer
37 views

how to repeat records in fastq n times efficiently?

How to iterate/repeat a record n times in a fastq file using bioawk? I wrote a python code using biopython, but it is very very slow. So, I am wondering if I can get some help by using bioawk. Thank ...
0
votes
1answer
46 views

Nvidia Parabrick fq2bam pipeline error - No such file or directory

I am trying to implement Nvidia-parabrick fq2bam pipeline to process my WES dataset. The reason for opting this pipeline is the huge number of samples (1004) which take many months to process for ...
2
votes
1answer
60 views

Merging several fq.gz files or R1 and R2 classes into a single one

I have the following files: ...
0
votes
1answer
115 views

How to find the number of contigs produced? N50 length in base pairs? N90 length in base pairs?

I am having trouble with some underlying questions about my project. I have ran a Trinity tool to create a trinity.fasta file. To determine some underlying questions, I used the utility asm_stats to ...
3
votes
0answers
24 views

Template files for bioattributes and meta-data [closed]

I am in process of submiting my FASTQ files to the SRA database. I am a little confused about how to fill the biosample attributes and SRA metadata. I would really appreciate if you anyone could share ...
1
vote
2answers
114 views

Can I eject the flow cell MinION from USB port when doing basecalling?

Can I eject the flow cell MinION from USB port when doing basecalling? Because its taking long and its not possible to wait for its finished, will it affects basecalling?
0
votes
0answers
20 views

Extract Illumina reads that match with respect to their coordinates on the genome from fastq files

I want to use BPP to estimate divergence times and population sizes of a set of species. I have a vcf file with SNPs called from RADseq. The problem is that BPP uses the multi-species coalescent model ...
2
votes
5answers
424 views

How to measure the total size of a fastq file in base pairs?

Or Kbps/Gbps. It feels like it should be conceptually very simple, but I can't seem to figure out the right combination of keywords to find it via my search engine. Help would be appreciated! I have ...
1
vote
3answers
990 views

Download multiple fastq files using fastq-dump

I want to download the following fastq files at the same time in Salmon: - SRR10611214 - SRR10611215 - SRR10611215 - SRR10611216 - SRR10611217 Is there a way ...
0
votes
0answers
67 views

nanopore QC measures on fastq file

I am working with virus nanopore sequencing data. I have to remove host genome from the reads. I want to run the QC on the fastq file after host genome subtraction. I have used nanoplot. It is slow. I ...
-3
votes
1answer
149 views

Bash script for automatic overlap merging of respective paired-end reads from samples

I have around 300 paired-end files from 150 samples (1 forward and 1 reverse read for each sample). I want to merge (by sequence overlap) respective forward and reverse reads for each of the samples. ...
2
votes
3answers
154 views

FASTQ file trimming

I have a FASTQ file: ...
0
votes
0answers
82 views

Unable to gunzip fastq files from ENA

I am trying to process fastq files in order to build gene co-expression networks (by following this tutorial). When I download any fastq file from ENA, and try to process it with the command: ...
2
votes
2answers
154 views

Extracting specific sections from FASTQ determined by positions

Given a FASTQ file, I'd like to generate a new FASTQ file including only certain subsections of the original sequences specified by their positions. For example, say I want to extract the ...
1
vote
1answer
655 views

How to split FASTQ reads without re-running `fastq-dump`?

I downloaded a few FASTQs from the SRA that were paired-end 76 bp. When I look at the FASTQs, I get something like this: ...
3
votes
1answer
175 views

What is a proper way for random subsampling of metagenomic data?

Let's say we have a metagenomic sample that is paired-end FASTQ files including 10,000,000 DNA reads collected using shotgun sequencing. How would one make a random subsample of the mentioned ...
1
vote
1answer
94 views

processing multiple fastq files with cutadapt

I have DNA sample from 5 pools, having 25 fastq files each. I am running cutadapt to remove the primers using this command ...
0
votes
1answer
74 views

Filtering raw sequencing reads

I have to filter the raw sequencing reads based on the following criteria: Remove reads containing adapters Remove reads containing N > 10% (N represents base that could not be determined) Remove ...
2
votes
2answers
133 views

Why does this naive Python paired Fastq reader work?

I wrote some throwaway code for ingesting paired-end reads from a Fastq file into memory. ...
4
votes
2answers
66 views

Is the quality score of fastq used somewhere besides trimming/fastqc?

In the fastq format every 4k+4-th line contains the positionwise qualityscore (ascii encoded): ...
7
votes
4answers
2k views

Convert FASTA to FASTQ with dummy quality scores

I have a FASTA file which I would like to convert into FASTQ format as the tool I want to use my data in requires it in FASTQ format. So dummy quality scores are fine. Note: I am not using any ...
3
votes
1answer
66 views

Tool for calibrating base quality scores?

A given sequencing machine assigns a 'certainty' to each base call in the form of a per-base quality score (FASTQ format). I have reads from several machines aligned to the corresponding reference (...
1
vote
1answer
50 views

Fastq-dump script download X spots or all

Im trying to write a script where an optional input of -X flag can be used, or if that info is not available download all reads. my script as follow: ...
2
votes
2answers
646 views

Error with BWA Mem input having multiple fastq files using cat and process substitution

Running BWA Mem on a number of paired end fastq files using process substitution on the inputs results in this error: ...
0
votes
1answer
249 views

SRA Toolkit execution problem

I am trying to install SRA Toolkit on MacOS, following all the instructions from NCBI website. It is installed but fastq-dump cannot be executed because "cannot execute binary files". I tried "chmod +...
2
votes
1answer
1k views

Fasterq-dump: --split-spot or -concatenate-reads?

After using files that I downloaded from the SRA with fasterq-dump, I realize I am not 100% sure that I have all the data. I noticed in my downstream analysis that I seem to be missing the .1 and .2 ...
2
votes
0answers
126 views

Nanopore FASTQ header specifications

Is there a specification anywhere for how a Nanopore FASTQ header should be formatted? I am creating strategies for generating test FASTQ files and would like to ensure I am generating "correct" ...
3
votes
2answers
214 views

Does this FASTQ data contain single or paired end calls?

I have this fastq data from GEO: ...
0
votes
1answer
426 views

How to convert a .fastq chip-seq file into a wig/bigwig track and how to extract chip-seq peaks?

I have a reference .fasta file and a raw .fastq file with chip-seq data. I am trying to create a bigwig track from the and .fastq and .fasta ref file of the raw signal. Then I would like to do some ...
0
votes
1answer
202 views

How to remove degenerate sequence (N4) at the 5' and 3' of the reads?

I have to analyse GSE114327. For that, I use GSE instruction based on GSM3139597. In that data processing section has written: FASTQ reads were subjected to adapter removal (cutadapt) per ...
2
votes
2answers
286 views

Filter reads belonging to unique sequences with threshold

I have CLL samples as fastq files and I want to remove those reads which have a unique sequence with less than 10 read counts each. I tried this by following way using awk to make it faster: ...
6
votes
1answer
1k views

Convert BAM to properly paired FASTQ files

I thought I had figured this one out. But apparently not. I need to convert a BAM file of paired-end alignments to two FASTQ files of paired reads to realign them, with a twist: I only want reads ...
4
votes
3answers
712 views

What do the FASTQ file names mean here?

I would like to run an analysis on Nanopore data. I'm trying to download sample data from https://github.com/nanopore-wgs-consortium/chm13. I would like to run minimap2 on the FASTQ files, resulting ...
3
votes
1answer
213 views

Fast processing of fastq data

I am trying to write python script for customized filtering for fastq file (size >3 GB). My proposed script is as follows: ...
4
votes
0answers
55 views

Determine reference for reference-compressed SRA file

Note: this question was also asked on Github. I have 241 SRA files that appear to be reference compressed. I didn't even know this was a thing until I tried to convert them to Fastq files without an ...
3
votes
2answers
246 views

Frequency of specific viral sequence in .BAM or .fastq

I was wondering if anyone had any experience 'counting' the frequency of a particular viral sequence in an individual's fastq sequence. So basically, counting the number of occurrences of a particular ...
1
vote
5answers
275 views

Testing for viral/bacterial infection FASTQ files

What's the best way to test if a pair of Illumina FASTQ files from blood DNA extraction contain any reads from viral/bacterial infection from DNA in human blood? Thanks in advance. EDIT: Looking at ...