這個(gè)專題叫Schedule for Single-cell RNA-seq workshop,那就把這個(gè)專題叫做【scRW】吧
第二課 Introduction to Single Cell RNA Sequencing
## <Introduction to Single Cell RNA Sequencing>
## 目錄
## 1 Common applications of single cell RNA sequencing.
## 2 Overview of single cell RNA sequencing platforms.
## 3 Modified scRNA-seq workflows
## 4 Sample preparation and experimental design.
## 5 Effects of sample prep and sample type on analysis
Bulk vs Single Cell RNA Sequencing (scRNA-seq)

-
Transcriptome Coverage (mRNA)
Transcriptome Coverage (mRNA) -
The World Between Bulk & scRNA-seq
The World Between Bulk & scRNA-seq
ps. throughput = the amount of material or items passing through a system or process.
1.Common Applications of scRNA-seq







More Cells or More Sequencing Reads?


2.Overview of single cell RNA sequencing platforms


2.1.1 Full Length Transcripts: SMART-seq (v3)

H Lim et al, Profiling Individual Human Embryonic Stem Cells by Quantitative RT-PCR. J. Vis. Exp. (87), e51408, 2014 (doi:10.3791/51408)
M Hagemann-Jensen et al, Single-cell RNA counting at allele- and isoform-resolution using Smart-seq3 bioRxiv 2019 (doi: https://doi.org/10.1101/817924)
2.1.2 Seq-Well: Honeycomb Biotechnologies


TM Gierahn et al, Seq-Well: portable, low-cost RNA sequencing of single cells at high throughput. Nat Methods. 2017 Apr;14(4):395-398. doi: 10.1038/nmeth.4179
2.1.3 Droplet scRNA-seq

2.1.4 inDrops Method Overview


A. M. Klein et al., Droplet barcoding for single-cell transcriptomics applied to embryonic stem cells, Cell 2015 (doi: 10.1016/j.cell.2015.04.044)
R. Zilionis et al., Single-cell barcoding and sequencing using droplet microfluidics, Nature Protocols 2016 (doi: 10.1038/nprot.2016.154 )
2.2.1 scRNA-seq Library Structure (inDrops)

2.2.2 10x Genomics Method Overview


2.2.3 Doublets / Cell Density

2.2.4 Scrublet: Computational Identification of Doublets

S. Wolock et al. Scrublet: computational identification of cell doublets in single-cell transcriptomic data, bioRxiv 2018 (DOI: 10.1101/357368)

2.2.5 On the Horizon: Spatial Transcriptomics

Rodriques et al, Slide-seq: A scalable technology for measuring genome-wide expression at high spatial resolution.
Science. 2019 Mar 29;363(6434):1463-1467.
3.Modified scRNA-seq workflows
3.1 Transcript Specific Library Prep





3.2 CITE-seq / Cell Hashing

3.3 Cell Hashing / CITE-seq

3.4 Label-Free Multiplexing of Patient Samples

3.5 10x Capture Sequence / Feature Barcode

3.5.1 10x V(D)J Immune Profiling & 5’ gene expression

3.5.2 10x V(D)J Immune Profiling

3.6 TotalSeq

4.Sample preparation and experimental design
4.1 Single Cell Core Sample Repertoire

4.2 Key to Success: Sample Preparation

4.3 Sample Preparation

4.3.1 Sample Preparation: increasing cell viability

4.3.2 Sample Preparation: single cell suspension

4.4 Sample preparation protocol varies by cell-type





4.5 Enrichment Methods: pros & cons

4.6 Enrichment Methods: cell staining

4.7 Sample Preparation: cell numbers
- 液滴法的最小細(xì)胞數(shù)為10,000-25,000
-需要約50-100個(gè)具有獨(dú)特轉(zhuǎn)錄組的細(xì)胞來(lái)鑒定種群群
-每ul 100-1000個(gè)細(xì)胞=每毫升100,000-1,000,000個(gè)細(xì)胞 - 通過(guò)血細(xì)胞計(jì)數(shù)器計(jì)數(shù)細(xì)胞–不要相信分類計(jì)數(shù)
-來(lái)自分選器的計(jì)數(shù)通常是實(shí)際細(xì)胞計(jì)數(shù)的? - 嘗試負(fù)選擇以去除不需要的細(xì)胞
- 在更broader的標(biāo)記上進(jìn)行分類以增加細(xì)胞數(shù)
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對(duì)于不可避免的低密度樣品
-將具有明顯表達(dá)特征的細(xì)胞摻入樣品中(沒懂)
sample preparation
4.8 Sample Preparation: buffers

確保緩沖液不含鈣,鎂,EDTA或肝素(抑制RT-PCR)

4.9 Sample Preparation: viability checks 樣品制備:可行性檢查
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檢查樣品隨時(shí)間的生存能力
-如果生存能力在短時(shí)間內(nèi)降低,這將反映在轉(zhuǎn)錄數(shù)據(jù)中;
-線粒體讀取計(jì)數(shù)很高。 -
檢查單細(xì)胞懸液上清液中是否存在游離的浮動(dòng)RNA(Ribogreen)
-在所有樣品中產(chǎn)生背景噪音并使分析復(fù)雜化; -
臺(tái)盼藍(lán)trypan陽(yáng)性的死細(xì)胞數(shù)量是和廢掉的reads數(shù)量是呈正比的
-如果在封裝時(shí)有30%的細(xì)胞死亡,那么最多將可以使用70%的測(cè)序數(shù)據(jù)。
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4.10 Sample Preparation: dead cell removal
- FACS out dead cells
-Will have all associated complications of FACS. - Miltenyi dead cell removal kit
-Magnetic beads used to remove dead cells & debris.
值得深思的問(wèn)題
- 您要去除多少死細(xì)胞?
- 這對(duì)您正在研究的生物學(xué)意味著什么?
- 記錄您的樣品制備元數(shù)據(jù)?。?!
4.11 Sample Preparation: cryopreservation
- 各種冷凍保存技術(shù)對(duì)樣本(PBMC或細(xì)胞系)有幾篇論文的相關(guān)報(bào)道。
- 冷凍保存成功與否取決于樣品類型。
- 血液細(xì)胞和免疫細(xì)胞冷凍效果很好。
- 關(guān)鍵是補(bǔ)液后細(xì)胞的活力。
- 將Nuc-seq作為冷凍保存細(xì)胞的選項(xiàng)。

- 冷凍時(shí)組織的質(zhì)量是下游數(shù)據(jù)質(zhì)量的主要因素。
- 單細(xì)胞核心已將細(xì)胞冷凍在補(bǔ)充了5%DMSO的標(biāo)準(zhǔn)生長(zhǎng)培養(yǎng)基中,效果最佳。
- 觀察到解凍后原代細(xì)胞具有20%的細(xì)胞死亡。
-
如果要冷凍組織以備后用,您可能需要考慮在BAM Banker冷凍保存劑中冷凍保存50 mg組織塊。
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4.12 Sample Preparation: single nuclei RNA-seq
- 從目標(biāo)樣品中提取核。
- 去除死細(xì)胞/垂死細(xì)胞的轉(zhuǎn)錄噪音。
- 最常用于神經(jīng)元樣本。
- 適用于速凍臨床樣品。
- 多項(xiàng)研究表明核轉(zhuǎn)錄本占整個(gè)細(xì)胞轉(zhuǎn)錄本的很大一部分。
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由于內(nèi)含子和非編碼RNA的存在,分析更加困難。
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4.13 Best practices to obtain high quality sample

sample prep地址
-https://www.protocols.io/
-https://support.10xgenomics.com/single-cell-geneexpression/sample-prep
-https://community.10xgenomics.com/


5.Effects of sample prep and sample type on analysis
5.1 How Sample Prep Effects Data


5.2 Data Analysis: Quality Control (QC) metrics

5.2 關(guān)于scRNA-seq的最終想法










