The concept of CLC Single Cell Analysis Module

CLC Single Cell Analysis Module 24.0 enables the study of single cell RNA (scRNA-Seq) data, including RNA velocity, spatial transcriptomics, Assay for Transposase-Accessible Chromatin (scATAC-Seq) samples, and T and B cell receptors (scTCR-Seq and scBCR-Seq, collectively known as scV(D)J-Seq). The comprehensive toolbox includes tools for analyzing the different types of data both separately and jointly.

scRNA-Seq

Tools are available for quality control and normalization, noise reduction and feature selection, clustering, cell type prediction, and differential expression. UMAP and tSNE plots can be overlaid with clusters, predicted cell types, or the expression of individual genes. Marker genes can be identified through analyses of differential gene expression and by gathering information from expression plots. Alternatively, cell type classifiers can be trained from pre-labeled cells. Two pre-trained classifiers are provided, and can be extended. Further, velocity analysis can be performed for data including both spliced and un-spliced reads, and an interactive phase portrait plot is produced. In addition, high-dimensional vector that predicts the future state of individual cells are added to the dimensionality reduction plots. The provided workflows can be easily adjusted to fit the chemistry and protocol of the data and are a good starting point from either raw FASTQ or an imported Expression Matrix.

Spatial transcriptomics

A tool is available for importing spatial transcriptomics data from Space Ranger spatial outputs. The resulting plot can be overlaid with clusters, predicted cell types, or the expression of individual genes. Additionally, the plot can be linked to a UMAP or tSNE plot, such that the same visualization can be applied simultaneously to both plots.

scATAC-Seq

A complete pipeline from peak calling and footprinting to analysis of differential accessibility is provided. The peak read mappings can be slit into minor sub-populations and visualized in a Tracklist. It is also possible to generate UMAP and tSNE plots from the peak matrix. Further, three workflows are provided starting either from reads or imported matrices.

scV(D)J-Seq

After the initial identification of clonotypes in the sample, these can be further filtered, combined across samples and the sample-level immune repertoires can be compared with regards to diversity estimates, gene usage, etc. UMAP and tSNE plots from matched scRNA-Seq data can be overlaid with clonotype information, once this is converted to Cell Annotations. The provided workflows are a good starting point from either raw FASTQ or imported Cell Clonotypes. Additionally, workflows are available for the joint analysis of both scRNA-Seq and scV(D)J-Seq data.

Selection of algorithms

The algorithms implemented have been selected to be the best performing at the time of development as assessed by independent paper reviews. All algorithms have been re-implemented in Java with the aim of being able to scale to large data sets and run on a wide range of hardware. Internal benchmarks have been conducted to select the best performing algorithm for predicting cell types, which is one of the key features in this software package. The manual provides detailed descriptions of the chosen algorithms, how to adjust parameters for better performance, and how to interpret results.