Single-cell RNA-seq analysis workflow

  • #SingleCellRNAseq
  • #Seurat
  • #CellTypeAnnotation
  • #Microglia

2024

GitHub

UMAP of marker-defined single-cell clusters with cluster labels and a fine-label legend.
Marker-defined hierarchical annotation of single-cell clusters.

Overview

I developed an R workflow for single-cell RNA-seq analysis, from quality control and cell-type annotation to composition analysis and microglial subclustering. One example run applies the workflow to control and LPS-exposed mouse brains.

Approach

  1. Preprocess the data and assess quality by sample and condition.
  2. Identify cell clusters and check annotations against marker expression.
  3. Compare cell-type proportions across samples and conditions.
  4. Analyze microglial subpopulations in greater detail.

Cell-type annotation

After quality control and preprocessing in Seurat, I used PCA and clustering to identify groups of cells. I checked cell-type annotations against marker-gene expression and compared cell-type proportions across samples and conditions.

Microglial analysis

I then analyzed the microglia separately, repeating normalization and clustering within this population. The analysis recorded cell counts by sample and explored candidate damage-response states.

Recorded outputs

The R scripts, processed objects, figures and logs record each stage of the analysis.

  • Quality control: sample- and condition-level violin plots and QC scatter plots.
  • Cell atlas: PCA and UMAP views, cluster views, and refined cell-type annotation.
  • Annotation checks: marker dot plots by cluster and cell type.
  • Composition: cell-type proportions shown by sample and condition.

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