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saRNA Synthesis
Small activating RNA (saRNA) is a class of synthetic short double-stranded RNA, typically 21–30 nt long, that targets gene promoter regions and upregulates target gene expression at the transcriptional level through RNA activation (RNAa).
We provide standard saRNA synthesis and four-candidate sequence packages, with synthesis and quality testing performed as agreed and sequence identity verified.
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  • 8business days

    Standard turnaround time

  • QC

    Sequence verified

  • ≥ 75%

    OPC purity

  • ≥ 2fold

    Four-candidate sequence package

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Introduction
Service Advantages
Product Comparison
Service Details
Service Workflow
Delivery Standards
Quality Control Standards
Applications
Frequently Asked Questions
saRNA Synthesis
Four-Candidate saRNA Package

saRNA Synthesis

Target Promoters to Activate Endogenous Gene Expression at the Transcriptional Level

Small activating RNA (saRNA) is a class of artificially synthesized short double-stranded RNA, typically 21–30 nt, that targets specific sequences in gene-promoter regions and uses the endogenous RNA activation (RNAa) mechanism to upregulate target-gene expression at the transcriptional level.

saRNA and siRNA act through opposite mechanisms. siRNA uses RNAi-mediated mRNA degradation to knock down genes, whereas saRNA uses RNAa-mediated transcriptional activation to upregulate genes. After saRNA enters the cell, the antisense strand is loaded by AGO2. The complex enters the nucleus, binds a specific sequence in the target-gene promoter, recruits the RITA complex, promotes chromatin opening, and enhances RNA polymerase recruitment.

  • Standard saRNA synthesis: chemically synthesized double-stranded RNA
  • Modified saRNA synthesis: supports 2'-OMe, fluorescent labeling, and other modifications
  • Synthesis and quality testing are performed according to the agreed sequence, with sequence accuracy confirmed

saRNA Synthesis Package

A four-candidate sequence package for screening candidates that effectively activate target-gene expression

The four-candidate saRNA package designs four saRNAs targeting the promoter region of a target gene. Under standard conditions, at least one is expected to activate target-gene expression effectively, making it suitable for customers without a validated target sequence.

Performance criteria:At a transfection efficiency of >80%, at least one saRNA is expected to achieve ≥2-fold activation of target-gene mRNA.

  • Target-gene saRNA: 4 target sites, 10 nmol (4 OD) per target site
  • Includes a negative control, FAM-labeled negative control, and positive-control siRNA
  • If the agreed criteria are not met, four new target-site saRNAs will be redesigned and synthesized at no charge after evaluation.

Service Advantages

One-stop saRNA service with professional design, candidate-sequence packages, and comprehensive quality control
  • Advanced Synthesis Platform · Optional MS Verification
    Using a mature RNA chemical-synthesis platform, synthesis and quality testing are performed according to the agreed sequence, with sequence accuracy confirmed. OPC purification provides high batch-to-batch consistency.
  • Professional Design Team · Promoter-Target Optimization
    Screen targets for high activation efficiency using principles including 30–50% GC content, avoidance of CpG-rich regions, terminal overhangs, and thermodynamic stability.
  • Four-Candidate Package · Reduced Screening Risk
    At least one of four saRNAs is expected to achieve ≥2-fold activation. If the agreed criteria are not met, redesign is provided as specified to reduce promoter-target screening risk.
  • Complete Control System
    Includes a negative control, FAM-labeled control, and positive-control siRNA to verify specificity, transfection efficiency, and the experimental system, respectively.
  • Flexible Scale · Fast Delivery
    Available from 5 nmol to milligram scale. Standard saRNA is delivered in 8 business days, with support for 2'-OMe, fluorescent labeling, and other chemical modifications.
  • One-Stop Upstream and Downstream Services
    Integrated services include target-sequence design, gene synthesis, chemically modified saRNA, and miRNA mimic/inhibitor products, covering both gene upregulation and downregulation needs.

saRNA vs siRNA

Opposite Directions of Action: Choose a Gene-Upregulation or Knockdown Tool Based on Your Goal
Comparison Dimension saRNA (Small Activating RNA · This Service) siRNA (Small Interfering RNA)
Direction of Action Gene activation (upregulation) Gene silencing (knockdown)
Mechanism RNAa（RNA activation） RNAi（RNA interference）
Target Location Gene promoter region mRNA (coding region or 3' UTR)
Level of Action Transcriptional level (promotes transcription) Post-transcriptional level (degrades mRNA)
Key Proteins AGO2 → nuclear entry → RITA complex AGO2 → RISC → mRNA cleavage
Effect Type Gene upregulation (gain of function) Gene knockdown (loss of function)
Onset Slower (requires nuclear entry and chromatin remodeling, 48–96 h) Fast (direct RISC cleavage, 24–72 h)
Effect Duration Long-lasting (epigenetic changes may persist) Transient (3–7 days)
Design Difficulty Higher (promoter-target screening is challenging) Lower (more mRNA target options)
Package Assurance Four-candidate package (at least 1 of 4 achieves ≥2-fold activation) Three-candidate package (at least 1 of 3 achieves ≥70% knockdown)
Applications Tumor-suppressor gene activation and gene-function upregulation studies Gene-function knockdown, signaling-pathway analysis, and high-throughput screening

Service Details

Custom synthesis and four-candidate sequence packages
Custom saRNA synthesis:Customers provide saRNA sequence information for custom synthesis. Synthesis and quality testing are performed according to the agreed sequence, with sequence accuracy confirmed. Activation performance should be evaluated in the context of experimental conditions. For candidate-sequence screening, the four-candidate package is recommended.
Service Item Scale Purification Turnaround Time Notes
Standard saRNA Synthesis
 From 5 nmol OPC 8 business days Chemically synthesized double-stranded RNA, 21–30 nt
Chemical ModificationsaRNA
 From 5 nmol OPC 8 business days Supports 2'-OMe, fluorescent labeling, and other modifications
Four-Candidate saRNA Package:Four saRNAs are designed for a specific gene-promoter region; under standard conditions, at least one is expected to activate target-gene expression effectively.
Package Contents Scale Purification
Target-gene saRNA (4 target sites)
 10 nmol (4 OD) per target site OPC
Negative-Control saRNA
 2.5nmol（1OD） OPC
FAM-Labeled Negative-Control saRNA
 2.5nmol（1OD） OPC
Positive Control siRNA
 2.5nmol（1OD） OPC

Performance criteria:At a transfection efficiency of >80%, at least one saRNA is expected to achieve ≥2-fold activation at the mRNA level. If the agreed criteria are not met, the customer may provide quantitative data for the four saRNAs and controls for evaluation, after which four targets will be redesigned and synthesized at no charge. If two rounds do not achieve the expected effect, no further resynthesis is provided.

Service Workflow

Four steps from requirement submission to delivery of lyophilized custom saRNA
  • Submit Requirements
    Provide the saRNA sequence, or provide the target-gene information and species so that we can design promoter targets. Specify the scale and modification requirements.
  • Confirm the Plan
    Receive the project plan, turnaround time, and quotation within 1–2 business days.
  • Synthesis and Quality Control
    After contract confirmation, complete synthesis, annealing, purification, and optional MS verification, and issue a QC report.
  • Delivery and Support
    Ship lyophilized product with synthesis and optional mass-spectrometry reports, provide transfection consultation, and redesign the four-candidate package as specified if the agreed criteria are not met.

Delivery Standards

Complete reports are delivered with the lyophilized saRNA
  • Lyophilized saRNA
    Aliquoted at 1 OD; store at -20°C protected from light and reconstitute before use.
  • RNA Synthesis Report
    Includes the saRNA sequence, molecular weight, purification method, OD value/concentration, and related information.
  • Mass Spectrometry Report (Optional)
    An optional MS spectrum verifies the molecular weight of the synthesized sequence.
  • Instructions for Use
    Includes the reconstitution method, storage recommendations, and reference transfection conditions.

Quality Control Standards

Comprehensive quality control covering sequence, purity, duplex formation, and appearance
QC Item Test Method Acceptance Criteria
Sequence Accuracy Molecular-weight determination by mass spectrometry (MS) (optional) Deviation between measured and theoretical molecular weight ≤0.1%
Purity OPC ≥75%
Duplex Formation Native PAGE Duplex proportion ≥85%
Appearance Visual Inspection White or off-white lyophilized powder

Synthesis and quality testing are performed according to the agreed sequence, with sequence accuracy confirmed.

Applications

Covering gene activation, functional studies, pathway analysis, and therapeutic development

Tumor-Suppressor Gene Activation

Target promoters to reverse epigenetic silencing, reactivate tumor-suppressor expression such as the p21 and p53 pathways, and inhibit tumor-cell proliferation, invasion, and migration.

Gene Gain-of-Function Studies

Activate endogenous genes while preserving native post-transcriptional regulation, alternative splicing, and protein modification for a more physiological state.

Signaling-Pathway Upregulation Studies

Activate key nodes such as receptors, kinases, or transcription factors and combine with siRNA knockdown for bidirectional validation of gene function.

Gene-Therapy Development

Activate endogenous genes without introducing exogenous DNA or altering the genomic sequence, making the approach suitable for loss-of-function genetic diseases and cancer research.

Epigenetics Research

Study chromatin remodeling, histone modifications such as H3K4me3/H3K27ac, DNA-methylation changes, and transcriptional regulatory networks.

Frequently Asked Questions

Frequently asked questions about saRNA synthesis, performance assurance, and applications
What is the difference between saRNA and an overexpression vector?
Overexpression vectors introduce exogenous cDNA, often with a strong promoter, resulting in high expression but lacking native regulation. saRNA activates endogenous genes while preserving native splicing and modification, producing a more physiological expression pattern. Overexpression is suitable when very high expression is required, whereas saRNA is better suited to functional studies under physiological conditions.
How long does saRNA-mediated activation last?
mRNA activation generally lasts about 3–7 days, similar to siRNA. Some saRNAs can induce epigenetic changes such as histone methylation, extending the effect for several weeks. Repeated transfection or chemical modification can further extend the duration.
What factors affect saRNA activation efficiency?
Promoter chromatin state, target-sequence affinity for AGO2, cell type, and transfection efficiency (recommended >80%) all affect performance. Genes with high basal expression may show a ceiling effect.
Why does the four-candidate saRNA package use siRNA rather than saRNA as the positive control?
Validated saRNA positive controls are limited and highly gene-dependent. siRNA knockdown is stable and reliable and can verify whether the transfection and detection systems are functioning properly. If knockdown fails, the experimental system should be troubleshot before the target sequence.
Can saRNA activate multiple genes at the same time?
Yes, but saRNAs must be designed separately for each gene promoter and then co-transfected. Consider the total RNA amount and transfection efficiency; validate each single target before testing combinations.
Can saRNA activate non-target genes?
Off-target risks mainly include promoter-homology effects and miRNA-like effects. Our design process includes genome-wide promoter-homology screening and seed-region off-target analysis, and we recommend a negative control to verify specificity.
What advantages does saRNA offer compared with CRISPRa?
CRISPRa requires delivery of dCas9 and sgRNA, which is relatively large and difficult to deliver. saRNA is chemically synthesized, easier to deliver, has no genomic-integration risk, and provides reversible, time-controlled activity. CRISPRa is suitable for long-term activation studies, whereas saRNA is suitable for short-term functional studies and early drug-development validation.
Can saRNA be used in vivo?
Yes. Chemical modifications such as 2'-OMe can improve serum stability and in vivo half-life, while carriers such as lipid nanoparticles (LNPs) can enable targeted delivery. Because saRNA does not alter the genomic sequence, it has potential in therapeutic development for cancer and genetic diseases.

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