This is a test version of Biostars. For the public version, visit https://www.biostars.org.
fastq-dump unable to separate fastq files from scRNA-seq SRA files

Hi all,

I recently downloaded a scRNA-seq file (SRR12661516) using sratoolkit. Then I needed to get the fastq files as I plan to upload the resulting fastq files to 10X genomics cloud for a new analysis. I used fastq-dump --split-3 SRR12661516 command to get the fastq files. I expected to get 3 fastq files:

SRR12661516_S1_L001_I1_001.fastq
SRR12661516_S1_L001_R1_001.fastq
SRR12661516_S1_L001_R2_001.fastq

Unfortunately, I got a fastq file named SRR12661516_pass.fastq. Can someone explain why I get this output? Also, I would appreciate it if you could help me to get the required fastq files. Thank you

sra sratoolkit fastq-dump scrna-seq

1 answer

I was able to get three expected files by doing (sra-toolkit v.3.0.1)

$ fastq-dump -F --split-files SRR12661516

$ head -4 SRR12661516*
==> SRR12661516_1.fastq <==
@NS500422:619:HM2FNBGX5:1:11101:9269:1047
GCACAATG
+NS500422:619:HM2FNBGX5:1:11101:9269:1047
AA/AAEAE

==> SRR12661516_2.fastq <==
@NS500422:619:HM2FNBGX5:1:11101:9269:1047
AAGTCNGGTAGTAGTAAAAACAGGTA
+NS500422:619:HM2FNBGX5:1:11101:9269:1047
AAAAA#EEEEEEEEEEEEEEEEEEEE

==> SRR12661516_3.fastq <==
@NS500422:619:HM2FNBGX5:1:11101:9269:1047
NACAAGTCAANTANTACAATNANATATNATACTNNTNANATGANTATTNNNAATANNN
+NS500422:619:HM2FNBGX5:1:11101:9269:1047
#AAA//////#/6#/6////#/#////#///6/##/#/#//6/#<A6/###/<</###

You will need to rename the files in the format cellranger expects (I1,R1, R2) manually.

Hi GenoMax, Thanks for your help. I also found suggestions from this link and was able to get three files as you have also shown here. Yeah, I feel the same that I have to rename the sample according to cellranger format.

Accept GenoMax's answer if it solves your problem.

Log in to answer this question.