Buyer’s Guide

Simple, customized
RNA-Seq workflows
Evaluating options for next-generation
RNA sequencing

Overcome limitationswith RNA-Seq
Next-generation sequencing (NGS) has revolutionized the study of the transcriptome. Sequencing data that once took years
to generate can now be produced in a matter of days or hours. Advances in RNA enable simpler, easier workflows from library
preparation to data analysis with highly accurate results.
RNA-Seq offers many advantages over previous methods such as qPCR and gene expression (GEX) arrays. RNA-Seq provides
a wider dynamic range than GEX arrays, resulting in greater sensitivity and accuracy.1 And unlike both qPCR and GEX arrays,
RNA-Seq can detect both known and novel features, enabling analysis of the transcriptome without the limitation of priorknowledge.2 Furthermore, RNA-Seq is a popular choice for both model and non-model species, even when genetic tools
and resources are limited.
The advantages of RNA-Seq and its impact on research can be seen through the rapid increase in RNA-Seq publications
and the increasing success of grant proposals for gene expression studies including RNA-Seq. (Figure 1)
RNA-Seq publications & funding
$500

35000

$450

30000

$400
$350
$300

20000

$250
15000

$200

Funding

Publications

25000

$150

10000

$100
5000$50$-2009

2010

2011

2012

2013

2014

2015

2016

2017

Figure 1: Comparison of publications and NIH grant awards using Uber Research Dimensions Database for publications and funding
using the search term “RNA-Seq”.3

With Illumina RNA sequencing workflows, RNA-Seq is more accessible than ever before. The most commonly used RNA analysis
pipelines are now available through a simple, click-and-go user interface, which means bioinformatic expertise is no longerrequired. Illumina library preparation is available for a broad range of sample types including low-quality samples, such as paraffinembedded (FFPE) tissue, and for a wide range of input amounts from normal tissue down to the single cell. If you have legacy
gene expression data generated on other platforms, such as GEX arrays or qPCR, software solutions are available to integratethese datasets with RNA-Seq data for experimental continuity.

2

Step 1. What scientic questions or applications am I interested in?
The first step in RNA sequencing begins with identifying the experimental question or application. What are you interested
in studying? Furthermore, are you interested in studying expression from bulk tissue or single cell?
Gene Expression Profiling – Understand and quantify the coding transcriptome (RNA exome).
Whole-Transcriptome Sequencing – Analyze both coding and noncoding transcripts.
Transcriptome Discovery – Identify novel features such as gene fusions, SNVs, splice junctions, and transcript isofoms.
Small RNA Sequencing – Study small RNA species such as miRNAs and other small RNAs with a 5’-phosphate and a3’-hydroxyl group.
Single-Cell RNA Sequencing – Study the individual contribution of single cells in complex tissues by profiling the transcriptome.

Step 2. What are my study design requirements?
The next step in the process involves understanding your study design needs. The list below describes common study design
requirements that will impact your choice of workflow, from library prep to data analysis.
Study Information Required – Determine the kind of figures and tables you want to include in your publication
or grant application.
Sample Type – Whether your samples are human, nonhuman, plant-based, or microbial, choose library preparation kits designed
for the specific sample type.
Sample Quality – For low quality or degraded samples, such as FFPE preserved samples, select library preparation solutions
optimized for low quality samples.
Sample Abundance – Will your RNA be derived from cell culture, single cells, or another source? Many library preparation kits
are optimized for low-quantity or single-cell samples.
Customized or ‘Out of the Box’ – Do current out-of-the-box solutions meet your needs? Evaluate whether you have the timeand resources for creating new methods or customizing existing assays.
Labor Requirements – Hands-on time (the time technicians must spend managing and monitoring the workflow), walk-away time(the ability to leave the workflow without having to intervene), total assay time, and automation options are important metrics fordetermining labor requirements.
Technical Expertise – Before implementing a study, determine what skill sets will be required from library preparation throughdata analysis and ensure that users are appropriately trained.

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Step 3. What factors will impact my RNA-Seq study cost?
A key consideration when designing an RNA-Seq study is the cost. The factors listed below can be used to calculate
RNA-Seq study costs. (For examples of common study objective and associated Illumina workflows, see the workflow sectionof this brochure.)
Study Size and Replicates – Determine the total number of samples in your study and assess whether or not you will needto prepare and run replicates.
Sample Throughput – How many samples do you need to run per day/week/month? These requirements will help determine
the library kit configuration and sequencing instrument that will best meet your throughput needs.
Read Depth – How many reads per sample will you need? The number of reads required depends on the goals of the study.
For example, gene count measurements typically require lower read depth compared to measuring low-expressing genes or
identification of novel features. While read depth requirements are ultimately based on the preferences of the investigator,
guidance provided by published research, resources such as the ENCODE Experimental Guidelines for ENCODE3 RNA-seq4
as well as Illumina Technical Support provide an excellent starting point for first-time users.

Tips for Reducing RNA sequencing costs• Maximize multiplexing when possible.
• Reduce the overall number of sequencing runs by using an Illumina
sequencing instrument with the appropriate throughput capacity.
• Perform all pre-library and post-library preparation QC steps.
• Consider automation options vs labor costs.
• Perform a pilot study to test library preparation and analysis pipeline.

4Illumina RNA-Seq workflow examples
After gathering information about your study goals, design requirements, and budget, you can begin to build a workflow tailored toyour specific research needs. The examples below illustrate four of the most common RNA sequencing workflows.

Workflow example #1• I want to focus on the coding transcriptome, and I want to quantify gene expression at the gene level, with one abundancevalue generated per gene.
Method: Gene Expression Profiling(10 million reads per sample, 1x50 bp min read length recommended)
Library Prep Kit

Sequencing Platforms

TruSeq™ Stranded mRNA
Library Prep Kit
Cost-efficient, scalable library preparation formRNA-Seq, with precise measurement ofstrand orientation. For standard RNA samples.*Throughput(total reads)**

Systems

25 million reads or less

MiniSeq™ or MiSeq™ Systems

TruSeq RNA Exome: Focus the discovery
power of RNA-Seq on difficult RNA samples,for a high-throughput and cost effective solution
analyzing the RNA exome.

130 to 400 million

NextSeq™ Systems

300 million to 2.5 billion

HiSeq™ Systems

800 million to 10 billion

NovaSeq™ Systems

Data Analysis Software
RNA Express App in BaseSpace™
Align RNA-Seq reads with the STARaligner and assign reads to genes.
Perform differential gene expression
with DESeq2.

*Standard samples include fresh or frozen tissue (not low quality or FFPE samples).
**Number of reads will depend on platform and flow cell configuration. For more information on instrument, flow cell, and reagent choice
visit www.illumina.com/systems/sequencing-platforms.html or www.illumina.com/library-prep-array-kit-selector.html.

5Illumina RNA-Seq workflow examples continued
Workflow example #2• I want to focus on the RNA exome, and I want to quantify gene expression by analyzing abundance values for every transcript
isoform from each gene (multiple abundance values per gene).
• I also want to identify novel transcript isoforms, SNVs, gene fusions, and/or identify allele-specific expression.
Method: mRNA-Seq(25 million reads per sample, min read length 2 x 75 bp)
Library Prep Kit

Sequencing Platforms

TruSeq Stranded mRNA
Library Prep Kit
Cost-efficient, scalable library preparation formRNA-Seq, with precise measurement of strandorientation. For standard RNA samples.*Throughput(total reads)**

Systems

25 million reads or lessMiniSeq or MiSeq Systems

TruSeq RNA Exome Library Prep KitStreamlined solution for mRNA-seq of low quality/
FFPE samples. Focus the discovery power ofRNA-Seq on difficult RNA samples, for a highthroughput and cost effective solution analyzing
the RNA Exome.

130 to 400 million

NextSeq Systems

300 million to 2.5 billion

HiSeq Systems

800 million to 10 billion

NovaSeq Systems

Data Analysis Software
RNA Express App in BaseSpace
Align RNA-Seq reads with the STARaligner and assign reads to genes.
Perform differential gene expression
with DESeq2.
BaseSpace Correlation Engine
Compare expression profiles fromRNA-Seq, qPCR, and GEX arrays.
Perform integrated analysis between
DNA, RNA, and methylation studies.
Compare molecular profiles from yourown studies with results from curated
public data repositories.

*Standard samples include fresh or frozen tissue (not low quality or FFPE samples).
**Number of reads will depend on platform and flow cell configuration. For more information on instrument, flow cell, and reagent choice
visit www.illumina.com/systems/sequencing-platforms.html or http://www.illumina.com/library-prep-array-kit-selector.html.

For Research Use Only. Not for use in diagnostic procedures.

6Illumina RNA-Seq workflow examples continued
Workflow example #3• I want to focus on both coding and multiple forms of noncoding RNA.
• I want to analyze abundance values for every transcript isoform from each gene (multiple abundance values per gene).
• I also want to identify novel transcript isoforms, SNVs, gene fusions, and/or identify allele-specific expression.
Method: Total RNA Sequencing(Normal samples, 50 million reads per sample, recommended minimum read length 2x 75 bp)(Low-quality/FFPE samples, 100 million reads per sample, 2 × 75 bp run format)
Library Prep Kit

Sequencing Platforms

TruSeq™ Stranded Total RNA with
Ribo-Zero™ Human/Mouse/Rat
Standard* or FFPE samples. Provides efficientrRNA removal across human, mouse, and rat
as well as additional eukaryotic species.

Throughput(total reads)**

System

130 to 400 million

NextSeq Systems

TruSeq™ Stranded Total RNA with
Ribo-Zero™Gold
Standard* or FFPE samples. Removes bothcytoplasmic and mitochondrial rRNA.

300 million to 2.5 billion

HiSeq Systems

800 million to 10 billion

NovaSeq Systems

TruSeq™ Stranded Total RNA with
Ribo-Zero™ Plant
Standard* or low quality samples. Provides
efficient whole-transcriptome analysis of avariety of plant species.

Data Analysis Software
RNA Express App in BaseSpace™
Align RNA-Seq reads with the STARaligner and assign reads to genes.
Perform differential gene expression
with DESeq2.
BaseSpace Correlation Engine
Compare expression profiles from RNASeq, qPCR, and GEX arrays. Perform
integrated analysis between DNA, RNA,and methylation studies. Compare
molecular profiles from your own studies
with results from curated public datarepositories.

TruSeq™ Stranded Total RNA with
Ribo-Zero™ Globin
Enables efficient interrogation of valuable human,mouse, and rat blood samples, removing bothrRNA and globin mRNA in a single, rapid step.

*Standard samples include fresh or frozen tissue (not low quality or FFPE samples).
** Number of reads will depend on platform and flow cell configuration. For more information on instrument, flow cell, and reagent choice
visit www.illumina.com/systems/sequencing-platforms.html or http://www.illumina.com/library-prep-array-kit-selector.html.

For Research Use Only. Not for use in diagnostic procedures.

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Illumina RNA-Seq workflow examples continued
Workflow example #4• I want to profile hundreds to thousands of single cells in a given experiment.
Method: 3’ whole transcriptome RNA sequencing(Recommend 100k reads per cell, min 2 x 75 format)
Library Prep Kit
SureCell™ Whole Transcriptome Analysis 3’
Library Prep Kit (2 & 6 Cartridges Kits)

Sequencing Platforms
Throughput(total reads)**

System

130 to 400 million

NextSeq Systems

300 million to 2.5 billion

HiSeq Systems

800 million to 10 billion

NovaSeq Systems

Data Analysis SoftwareThe SureCell RNA Single-Cell App supports
data analysis for the Illumina Bio-Rad
Single-Cell Sequencing Solution. The App
enables streamlined data analysis for up
to 96 samples across multiple sequencing
runs and includes sequencing quality
control metrics, assignment of uniquetranscripts to single cells, exportable gene
expression matrices and various analysis
options for identification of subpopulations
and differentially expressed genes.
Tertiary analysis:
SeqGeq Software is a desktop application
for advanced data analysis, exploration,and visualization of single-cell gene
expression data developed by FlowJo, LLC.
SeqGeq Software features direct integration
with BaseSpace, powerful data reduction
and population identification tools.

*Standard samples include fresh or frozen tissue (not low quality or FFPE samples).
** Number of reads will depend on platform and flow cell configuration. For more information on instrument, flow cell, and reagent choice
visit www.illumina.com/systems/sequencing-platforms.html or http://www.illumina.com/library-prep-array-kit-selector.html.

For Research Use Only. Not for use in diagnostic procedures.

8Maximize performance and productivity with Illumina services,training, and consulting
Whether immediate help is needed during an instrument run, or in-depth consulting is required for workflows, Illumina can help.
Illumina customer service and support teams provide guidance from initial trainings, to instrument support, personalizedconsultations, and ongoing NGS education. Our support offerings include:

Illumina Technical Support• Global, 24/5 phone and email support in the Americas, Europe, and Asia-Pacific• Illumina TS specialists can perform desktop sharing with GoToAssist—a powerful tool for quick identificationand diagnosis of issues over the phone• For faster case handling, enter your case number at the main phone menu to be routed directly to the TS specialist
handling your case

Illumina University Training• Instructor-Led Training at Your Chosen Facility• Instructor-Led Training at an Illumina Training Center• Online Courses• Webinars

Illumina Consulting• Proof-of-Concept Services for instrument and library preparation testing• Concierge Services for design assistance and product optimization

Product Support Services• Tiered Instrument Service Plans + Add-On Services• Instrument Compliance Services• Instrument On-Demand Services
For more on Illumina support offerings, visit www.illumina.com/services/instrument-services-training.html

9References
1. Su Z, Labaj PP, Li S, et al. A comprehensive assessment of RNA-Seq accuracy, repodrucibility and information content
by the Sequencing Quality Control Consortium. Nature Biotech. 2014;32:903-914.
2. Wang Z, Gerstein M, Snyder M. RNA-Seq and revolutionary tool for transcritptomics. Nature Rev Genet. 2009;10:57-63.
3. www.uberresearch.com
4. www.encodeproject.org/about/experiment-guidelines

10Illumina • 1.800.809.4566 toll-free (US) • +1.858.202.4566 tel • techsupport@illumina.com • www.illumina.com
For Research Use Only. Not for use in diagnostic procedures.
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