"CB" is not present

[YuelinYao]

Hi, I follow the instruction in the tutorial in order to produce the loom file for scVelo. but when I run the velocyto tools dropest-bc-correct, it reports tag "CB" is not present in the bam file. Could you please help me to solve my problem? my step is as follow (the sample obtained from indrop seq so I follow the dropseq pipline): prefetch SRR8497641 #download sample from sra fastq-dump --split-files SRR8497641/SRR8497641.sra #transfer into fastaq droptag -c indrop_v3.xml -S -s SRR8497641_2.fastq SRR8497641_4.fastq SRR8497641_1.fastq ##droptag #alignment STAR --genomeDir refdata-cellranger-mm10-1.2.0/star
--readFilesIn SRR8497641_1.fastq.tagged.1.fastq.gz,SRR8497641_1.fastq.tagged.2.fastq.gz,SRR8497641_1.fastq.tagged.3.fastq.gz,SRR8497641_1.fastq.tagged.4.fastq.gz,SRR8497641_1.fastq.tagged.5.fastq.gz
--outSAMmultNmax 1
--runThreadN 6
--readNameSeparator space
--outSAMunmapped Within
--outSAMtype BAM SortedByCoordinate
--outFileNamePrefix SRR8497641_1
--readFilesCommand gunzip -c

#dropest dropest -m -V -b
-o SRR8497641/SRR8497641_dropEst
-g refdata-cellranger-mm10-1.2.0/genes/genes.gtf
-L eiEIBA
-c config_desc2.xml
-r SRR8497641_1.fastq.tagged.params.gz
SRR8497641_1Aligned.sortedByCoord.out.bam

###correct velocyto tools dropest-bc-correct SRR8497641_1Aligned.sortedByCoord.out.tagged.bam SRR8497641/SRR8497641_dropEst.rds

error: KeyError: "tag 'CB' not present"

additionally, I also download the sample SRR5945695 in order to follow the tutorial (which is indrop_v2), but it also reports KeyError: "tag 'CB' not present".

Anyone could help me solve this problem?

[WWXkenmo]

Hi, have you solved the bug, I currently encounter the same issue...

[bettycatherine]

I also encountered and fixed the problem. In case anyone need it, I posted here. The default setting of dropest-bc-correct read a barcode tag of "CB", however, the dropest write the bamfile with barcodes tagged with "CR" somehow. so I modified the dropest-bc-correct.py file by replacing "CB" with "CR", as well as run_dropest.py file, and everything went fine.