Blood Transcriptomics Redefined
Blood Transcriptomics
Whole blood is a readily accessible, minimally invasive sample type that can be easily collected and stored for a variety of analyses. Blood provides valuable insights into both health and disease states and is routinely used for diagnosis and clinical research.
Whole blood transcriptome sequencing is an RNA-Seq technique that offers a comprehensive analysis of gene expression, isoforms, and long non-coding RNAs in blood samples. RNA-Seq workflows specifically designed for whole blood samples accelerate discoveries by enabling researchers to conduct extensive non-invasive assays on a global scale in an unbiased manner. In addition, blood samples are often used in Drug Discovery workflows during early discovery, preclinical studies, and clinical trials. Biofluids, such as blood and plasma, are the sample types of choice for biomarker discovery, expression analysis, treatment and progression analyses and to study the effects of drugs or combination therapy.
What is the aim of your Blood Transcriptomics study?
Validated RNA-Seq workflows and services for blood sample characterization include classical whole transcriptome sequencing, small RNA-Seq, and cost-efficient global 3’ mRNA-Seq approaches ideal for accurate expression profiling in, e.g., cancer studies and drug discovery applications.
How are blood samples used for scientific and clinical research?
Whole blood is a heterogeneous biofluid containing a diverse population of cells including erythrocytes and leukocytes. Each cell type exhibits unique transcriptional profiles reflecting their specialized functions in the body and roles in the immune system. Due to this cellular heterogeneity, whole blood is a rich source of easily accessible gene expression information. RNA-Seq from blood samples provides valuable insights into the human transcriptome and delivers implications for health and disease. Blood can be easily collected (as liquid biopsy) even from large cohorts of individuals, it can be stabilized and stored for later RNA isolation, facilitating logistics and enabling multicenter studies, e.g., for drug discovery applications or cancer research. Blood draws and analyses are used to identify biomarkers or disease associated immune profiles, they accompany clinical trials for control and treatment groups and provide a means to assess a patient’s disease progression and their response to the applied therapy.
What are the main applications of blood samples for transcriptomics studies?
Liquid biopsy samples from blood provide information for the identification and detection of biomarkers for disease onset, progression, and treatment. As blood sampling can be done by minimally invasive collection, whole blood is often analyzed for oncology applications, to study cancer including liquid or blood cancer in children.
Common transcriptomics applications for blood samples
- Cancer Research, e.g., Acute Myeloid Leukemia
- Gene Expression Profiling
- Target Studies in Drug Development
- Mutation Detection
- Immune Profiling
- Biomarker Detection
- Neurodegenerative Disease Research
Challenges of RNA-Seq from whole blood samples
While blood is becoming a more and more important sample source, transcriptome sequencing of whole blood samples remains a challenge to researchers. Samples must be collected in a way that prevents coagulation and RNA degradation to enable further analysis. Compared to other sample types, blood contains approximately 10x more DNA than RNA posing a major challenge for highly sensitive methods such as RNA-Seq. DNase digest is therefore highly recommended to remove any genomic DNA contamination after RNA extraction.
In addition, blood consists of multiple cell types with erythrocytes being by far the most abundant type with ~95 % of all cells and leukocytes comprising only ~1 % or less. Consequently, globin transcripts from erythrocytes account for about 70 % of the total whole blood mRNA, concealing valuable information contained in the low abundant leukocyte fraction – which is the primary subject for blood transcriptome studies. Globin transcripts can dominate RNA-Seq data sets from blood samples masking the expression of other genes. Therefore, efficient removal of all globin mRNAs is key to ensure accurate expression profiling, whole transcriptome analysis, and detection of low-abundance transcripts. Dedicated solutions for RNA sequencing from whole blood samples can significantly increase data quality, ultimately ensuring higher quality results and the success of studies conducted using this sample type.
To learn more about best practices for RNA sequencing from blood samples, see our RNA Expertise blogs.
