Time | Topic | Instructor |
---|---|---|
13:30 - 13:45 | Workshop introduction | Radhika |
13:45 - 15:00 | Single-cell RNA-seq design and methods | Dr. Mandovi Chatterjee |
15:00 - 15:05 | Break | |
15:05 - 15:15 | scRNA-seq pre-reading discussion | Jihe |
15:15 - 15:55 | Quality control set-up | Radhika |
15:55 - 16:00 | Overview of self-learning materials and homework submission | Jihe |
I. Please study the contents and work through all the code within the following lessons:
-
Click here for a preview of this lesson
Before you start any analysis, it’s important to know whether or not you have good quality cells. At these early stages you can flag or remove samples that could produce erroneous results downstream.
In this lesson you will:
- Compute essential QC metrics for each sample
- Create plots to visualize metrics per sample
- Critically evaluate each plot and learn what each QC metric means
-
Overview of Clustering Workflow
Click here for a preview of this lesson
QC is complete, what's next?
In this lesson you will get a brief overview of the next steps in the scRNA-seq analysis workflow. It's good to have a big picture understanding before we get into the nitty gritty details!
-
Theory of Normalization and PCA
Click here for a preview of this lesson
Before we can begin the next steps of the workflow, we need to make sure you have a good understanding of two important concepts: normalization and Principal Components Analysis (PCA). These are two methods that will be utilized in the scRNA-seq analysis workflow, and this foundation will help you better navigate those steps.
-
Normalization and regressing out unwanted variation
Click here for a preview of this lesson
During the analysis we will be making lots of comparisons; between cells, between samples, or both. To make accurate comparisons of gene expression we need to first perform normalization. We also want to make sure that the differences we find are a true biolgical effect and not a result of other sources of unwanted variation .
In this lesson you will:
- Assess your data for any unwanted variation
- Normalize the data while also regressing out any identified sources of unwanted variation
II. Complete the exercises:
- Each lesson above contain exercises; please go through each of them.
- Copy over your R code from the exercises to this (downloadable) R script
- Upload the saved R script file to Dropbox day before the next class.
III. Run the code in this script to perform the steps of integration. We will discuss the code and theory in class.
- If you get stuck due to an error while runnning code in the lesson, email us
- Post any conceptual questions that you would like to have reviewed in class here.
Time | Topic | Instructor |
---|---|---|
13:30 - 14:40 | Self-learning lessons discussion | All |
14:40 - 14:45 | Break | |
14:45 - 16:00 | Integration | Radhika |
I. Please study the contents and work through all the code within the following lessons:
-
Click here for a preview of this lesson
From the UMAP visualization of our data we can see that the cells are positioned into groups. Our next task is to isolate clusters of cells that are most similar to one another based on gene expression.
In this lesson you will:
- Learn the theory behind clustering and how it is performed in Seurat
- Cluster cells and visualize them on the UMAP
-
Click here for a preview of this lesson
After separating cells into clusters, it is crtical to evaluate whether they are biologically meaningful or not. At this point we can also decide if we need to re-cluster and/or potentialy go back to a previous QC step.
In this lesson you will:
- Check to see that clusters are not influenced by uninteresting sources of variation
- Check to see whether the major principal components are driving the different clusters
- Explore the cell type identities by looking at the expression for known markers across the clusters.
-
Click here for a preview of this lesson
By this point, you have defined most of your clusters as representative populations of particular cell types. However, there may still some uncertanity and/or unknowns. This step in workflow is about using the gene expression data to identify genes that exhibit a significantly higher (or lower) level of expression for a partcular cluster of cells.
In this lesson, we idenitfy these lists of genes and use them to:
- Verify the identity of certain clusters
- Help surmise the identity of any unknown clusters
-
Complete the exercises:
- Each lesson above contain exercises; please go through each of them.
- Copy over your R code from the exercises to this (downloadable) R script
- Upload the saved R script file to Dropbox day before the next class.
- If you get stuck due to an error while runnning code in the lesson, email us
- Post any conceptual questions that you would like to have reviewed in class here.
Time | Topic | Instructor |
---|---|---|
13:30 - 14:30 | Self-learning lessons discussion | All |
14:30 - 14:40 | Workflow summary | Radhika |
14:40 - 14:45 | Break | |
14:45 - 15:30 | Discussion, Final Q & A | All |
15:30 - 16:00 | Wrap up | Jihe |
Differential expression between conditions
We have covered the analysis steps in quite a bit of detail for scRNA-seq exploration of cellular heterogeneity using the Seurat package. For more information on topics covered, we encourage you to take a look at the following resources:
- Seurat vignettes
- Seurat cheatsheet
- Satija Lab: Single Cell Genomics Day
- "Principal Component Analysis (PCA) clearly explained", a video from Josh Starmer
- Additional information about cell cycle scoring
- Using R on the O2 cluster
- Highlighted papers for sample processing steps (pre-sequencing):
- "Sampling time-dependent artifacts in single-cell genomics studies." Massoni-Badosa et al. 2019
- "Dissociation of solid tumor tissues with cold active protease for single-cell RNA-seq minimizes conserved collagenase-associated stress responses." O'Flanagan et al. 2020
- "Systematic assessment of tissue dissociation and storage biases in single-cell and single-nucleus RNA-seq workflows." Denisenko et al. 2020
- Azimuth reference-based analysis
- CellMarker resource
- Highlighted papers for single-nuclei RNA-seq:
- Ligand-receptor analysis with CellphoneDB
-
Other online scRNA-seq courses:
-
Resources for scRNA-seq Sample Prep: