Cell Ranger's pipelines analyze sequencing data produced from Chromium Single Cell Gene Expression. It also processes data generated by using Feature Barcode technology. The count
pipeline cannot be used to analyze Fixed RNA Profiling (FRP) data.
The analysis involves the following steps:
-
Run
cellranger mkfastq
,bcl-convert
, orbcl2fastq
on the Illumina BCL output folder to demultiplex and generate FASTQ files. -
Run
cellranger count
on each GEM well that was demultiplexed. If you created a Feature Barcode library alongside the Gene Expression library, you will pass them both tocellranger count
at this point. See Feature Barcode Analysis for details. -
Optionally, run
cellranger aggr
to aggregate multiple GEM wells from a single experiment that were analyzed bycellranger count
. -
Optionally, run
cellranger reanalyze
to rerun the secondary analysis on a library or aggregated set of libraries (i.e., PCA, t-SNE, and clustering) and fine-tune parameters.
For the following example, assume the Illumina BCL output is in a folder named /sequencing/140101_D00123_0111_AHAWT7ADXX
.
First, generate FASTQ files. For example, if the flow cell ID was HAWT7ADXX
and you use cellranger mkfastq
to demultiplex, the output FASTQ files will be in HAWT7ADXX/outs/fastq_path
.
If you are already starting with FASTQ files, you can skip this step and proceed directly to run cellranger count
.
To generate single cell feature counts for a single library, run cellranger count
with the following arguments. For a complete listing of the arguments accepted, see the Command Line Argument Reference below, or run cellranger count --help
. Cell Ranger must not be used for Single Cell Multiome Analysis. For Single Cell Multiome ATAC + Gene Expression libraries, use Cell Ranger ARC.
After determining these input arguments and customizing the code, run cellranger
:
cd /home/jdoe/runs
cellranger count --id=sample345 \
--transcriptome=/opt/refdata-gex-GRCh38-2020-A \
--fastqs=/home/jdoe/runs/HAWT7ADXX/outs/fastq_path \
--sample=mysample \
--localcores=8 \
--localmem=64
Following a series of checks to validate input arguments, cellranger count
pipeline stages will begin to run:
Martian Runtime - v4.0.8
Running preflight checks (please wait)...
Checking sample info...
Checking FASTQ folder...
Checking reference...
Checking optional arguments...
...
By default, Cell Ranger will use all of the cores available on your system to execute pipeline stages. You can specify a different number of cores to use with the --localcores
option; for example, --localcores=16
will limit Cell Ranger to using up to sixteen cores at once. Similarly, --localmem
will restrict the amount of memory (in GB) used by Cell Ranger.
The pipeline will create a new folder named with the sample ID you specified (e.g. /home/jdoe/runs/sample345
) for its output. If this folder already exists, Cell Ranger will assume it is an existing pipestance and attempt to resume running it.
A successful cellranger count
run should conclude with a message similar to this:
Outputs:
- Run summary HTML: /opt/sample345/outs/web_summary.html
- Run summary CSV: /opt/sample345/outs/metrics_summary.csv
- BAM: /opt/sample345/outs/possorted_genome_bam.bam
- BAM index: /opt/sample345/outs/possorted_genome_bam.bam.bai
- Filtered feature-barcode matrices MEX: /opt/sample345/outs/filtered_feature_bc_matrix
- Filtered feature-barcode matrices HDF5: /opt/sample345/outs/filtered_feature_bc_matrix.h5
- Unfiltered feature-barcode matrices MEX: /opt/sample345/outs/raw_feature_bc_matrix
- Unfiltered feature-barcode matrices HDF5: /opt/sample345/outs/raw_feature_bc_matrix.h5
- Secondary analysis output CSV: /opt/sample345/outs/analysis
- Per-molecule read information: /opt/sample345/outs/molecule_info.h5
- CRISPR-specific analysis: null
- Loupe Browser file: /opt/sample345/outs/cloupe.cloupe
- Feature Reference: null
- Target Panel File: null
Waiting 6 seconds for UI to do final refresh.
Pipestance completed successfully!
yyyy-mm-dd hh:mm:ss Shutting down.
Saving pipestance info to "tiny/tiny.mri.tgz"
The output of the pipeline will be contained in a folder named with the sample ID you specified (e.g. sample345
).
Once cellranger count
has successfully completed, you can browse the resulting web summary HTML file in any supported web browser and open the .cloupe
file in Loupe Browser. Refer to the Understanding Outputs 3' Gene Expression Outputs page for descriptions about all output files.
A list of all Cell Ranger count
arguments are provided on the Cell Ranger manual page.