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agomir/antagomir Synthesis
Agomirs and antagomirs are highly stable, chemically modified miRNA tools designed for in vivo animal studies. They are used for gain-of-function and loss-of-function studies of miRNAs, respectively.
From cellular mechanism discovery to animal model validation, we provide long-lasting, stable, and convenient in vivo miRNA research solutions.
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  • 5business days

    Fastest delivery time

  • > 90%

    HPLC purity

  • As agreed

    Quality verification for modification services

  • 1-5weeks

    Duration of effect after a single administration

首页 > Products > miRNA Synthesis > agomir/antagomir Synthesis >
Introduction
Product Comparison
Chemical Modification Strategy
Service Advantages
Service Details
Service Workflow
Delivery Standards
Quality Control Standards
In Vivo Administration Guide
Applications
Frequently Asked Questions
miRNA agomir/antagomir
agomir Synthesis
antagomir Synthesis

miRNA agomir/antagomir

From Cellular Mechanisms to Animal Validation

Agomirs and antagomirs are highly stable, chemically modified miRNA tools designed for in vivo animal studies. They are used for miRNA gain-of-function and loss-of-function studies, respectively.

They overcome the major limitations of in vitro tools such as mimics and inhibitors in vivo, including short half-life, nuclease degradation, and inefficient delivery, bridging cellular mechanism discovery and animal-model validation.

  • Agomirs are used to overexpress miRNAs by in vivo administration.
  • Antagomirs are used to silence specific miRNAs in vivo.
  • Direct administration without viral vectors or transfection reagents.
  • Optional MS verification of molecular weight; HPLC purity ≥90%.

agomir Synthesis

In Vivo Gain-of-Function — Fully Modified for Long-Lasting Stability

An agomir is a specially chemically modified miRNA mimic for in vivo miRNA overexpression (gain-of-function) studies. Like an in vitro mimic, it is a double-stranded RNA containing a guide strand and a passenger strand, but extensive chemical modification greatly improves in vivo stability and tissue distribution.

After administration, cholesterol-mediated membrane penetration enables agomir uptake into cells. The guide strand is loaded into the RISC complex to recognize and suppress target mRNA, producing gene silencing comparable to endogenous miRNA.

  • Stable and long-lasting: serum half-life is extended to several days, and a single administration can remain effective for 1–5 weeks.
  • Convenient delivery: supports local, intravenous, intraperitoneal, and other administration routes.
  • Strict quality control: optional MS verification of molecular weight plus HPLC purity ≥90%, with a complete QC report.

antagomir Synthesis

In Vivo Loss-of-Function — Fully Modified for Long-Lasting Stability

An antagomir is a specially chemically modified miRNA inhibitor used for in vivo miRNA silencing (loss-of-function) studies. Similar to an in vitro inhibitor, it is a single-stranded RNA fully complementary to the mature miRNA.

With high affinity, an antagomir specifically binds and sequesters endogenous mature miRNA to form a stable duplex, preventing miRNA loading into RISC; the duplex is subsequently cleared by endogenous cellular mechanisms.

  • Efficient silencing: a single administration can significantly reduce target miRNA activity.
  • Long-lasting activity: effects can persist for several weeks, up to 5–6 weeks.
  • Strict quality control: optional MS verification of molecular weight plus HPLC purity ≥90%, with a QC report.

Product Comparison: mimic/inhibitor vs agomir/antagomir

Select by Experimental Setting (In Vitro/In Vivo) and Functional Direction
Comparison miRNA mimic
(In Vitro)		 miRNA inhibitor
(In Vitro)		 miRNA agomir
(In Vivo)		 miRNA antagomir
(In Vivo)
Strand Type Double-Stranded RNA Single-Stranded RNA Double-Stranded RNA Single-Stranded RNA
Functional Direction miRNA Overexpression miRNA Inhibition miRNA Overexpression miRNA Inhibition
Chemical Modification Unmodified/Basic Modification Basic modifications such as 2'-OMe Cholesterol + PS + 2'
-OMe comprehensive modification		 Cholesterol + PS + 2'
-OMe comprehensive modification
Applicable Experiments In Vitro Cell Experiments In Vitro Cell Experiments In Vivo Animal Studies In Vivo Animal Studies
Administration Route Transfection Reagent-Mediated Delivery Transfection Reagent-Mediated Delivery Injection/Inhalation/Oral Gavage Injection/Inhalation/Oral Gavage
Serum Half-Life Short
(Minutes to Hours)		 Short Long
(Several Days)		 Long
(Several Days)
Duration of Effect 3–7 Days 3–7 Days 1–5 Weeks 1–5 Weeks
Requires Transfection Reagent Required Required Optional Optional

Detailed Chemical Modification Strategy

Multiple Chemical Modifications Synergistically Improve In Vivo Stability, Target Affinity, and Tissue Uptake
agomir Modification Strategy: modifications are primarily applied to the antisense (guide) strand to ensure its stability and RISC loading efficiency.
Modification Type Position Quantity
Cholesterol Antisense Strand 3' End 1
PS Antisense Strand 3' End 2
PS Antisense Strand 5' End 2
2'-OMe Sense + Antisense Strands Full Length
antagomir Modification Strategy: antagomir is a single-stranded RNA; full-length modification ensures in vivo stability.
Modification Type Position Quantity
Cholesterol 3' End 1
PS 3' End 22
PS 5' End 2
2'-OMe Full Length Full Length

2'-O-methyl (2'-OMe):Blocks nuclease recognition and cleavage, improves base-pair affinity for the target, and reduces activation of immune receptors such as TLRs.

Phosphorothioate (PS):Resists 3'/5' exonuclease degradation and extends half-life from minutes to days.

Cholesterol:Promotes cell-membrane association and endocytic uptake, enabling cellular entry without transfection reagents and enhancing accumulation in tissues such as the liver and intestine.

Service Advantages

Comprehensive Chemical Modification for In Vivo Quality and Long-Lasting Stability
  • Advanced Synthesis Platform · Optional Mass Spectrometry Verification
    Quality is verified using the agreed test items, with sequence identity confirmed; HPLC purification provides ≥90% purity and strong batch-to-batch consistency.
  • Comprehensive Chemical Modification · In Vivo-Grade Quality
    Triple chemical modification with cholesterol conjugation, phosphorothioate (PS) backbone, and 2'-O-methyl (2'-OMe) extends serum half-life from minutes to days.
  • Flexible Administration Routes
    No transfection reagent is required. Local, intravenous, intraperitoneal, and other administration routes are supported for different animal models and research needs.
  • Fast Delivery · 5 Business Days
    Agomir/antagomir products can be delivered in as few as 5 business days and support all species listed in miRBase, including human, mouse, and rat.
  • Stable and Long-Lasting
    A single agomir administration can remain effective for 1–5 weeks; antagomir activity can persist for several weeks, up to 5–6 weeks.
  • Rigorous Quality Control
    Optional MS verification of molecular weight, HPLC purity ≥90%, and a complete QC report for each batch, with consultation on in vivo administration plans and dose optimization.

Service Details

Provide the miRNA name or mature sequence to start synthesis
Service Item Scale Purification Turnaround Time Notes
agomir
 From 5 nmol OPC/HPLC 5 business days Double-stranded, with cholesterol, PS, and 2'-OMe modifications;
suitable for in vivo overexpression
antagomir
 From 5 nmol OPC/HPLC 5 business days Single-stranded, with cholesterol, PS, and 2'-OMe modifications;
suitable for in vivo inhibition
agomir NC
 From 2.5 nmol OPC/HPLC 5 business days Double-stranded unrelated sequence with the same modification design
antagomir NC
 From 2.5 nmol OPC/HPLC 5 business days Single-stranded unrelated sequence with the same modification design

Service note:Customers may provide the miRNA name (for example, hsa-miR-21-5p) or the mature sequence for direct synthesis. We can also assist in confirming conserved sequences across species.

Service Workflow

Four Steps from Requirement Submission to Lyophilized In Vivo-Grade miRNA Tool Delivery
  • Submit Requirements
    Provide the miRNA name (for example, hsa-miR-21-5p) or mature sequence, species, quantity, and whether a negative control is required.
  • Confirm the Plan
    Our technical team responds within 1 business day with the modification plan, calculated molecular weight, timeline, and quotation, and can assist in confirming conserved sequences across species.
  • Synthesis and Quality Control
    Complete chemical synthesis, cholesterol + PS + 2'-OMe modification, purification, and optional mass spectrometry verification, followed by a QC report.
  • Delivery and Support
    The lyophilized product is shipped with synthesis and mass spectrometry reports, plus consultation on in vivo administration plans and dose optimization.

Delivery Standards

Delivered to In Vivo-Grade Standards and Ready to Use After Reconstitution
  • agomir/antagomir Lyophilized Powder
    Aliquoted at 1 OD; store at -20°C protected from light and use after reconstitution.
  • RNA Synthesis Report
    Includes miRNA sequence, modification type/position/quantity, molecular weight, purification method, and OD value/concentration.
  • Mass Spectrometry Report (Optional)
    Provides an optional MS spectrum to verify the molecular weight after modification.
  • Purity Report
    For HPLC-grade products, a chromatogram is provided and purity is ≥90%.
  • Instructions for Use
    Includes reconstitution instructions, storage recommendations, and reference doses for in vivo administration.

Quality Control Standards

Comprehensive quality control covering sequence, modifications, purity, and appearance
QC Item Test Method Acceptance Criteria
Sequence and Modification Accuracy Molecular-weight determination by mass spectrometry (MS) (optional) Deviation between measured and theoretical modified molecular weight ≤0.1%
Purity HPLC/OPC OPC：≥75%；HPLC：≥90%
Duplex Formation (agomir) Native PAGE Duplex proportion ≥85%
Modification Efficiency (optional) LC-MS/MS Quality verification performed for the agreed items
Appearance Visual inspection White or off-white lyophilized powder

Each batch is supplied with the corresponding QC report to confirm suitability for in vivo animal experiments.

In Vivo Administration Guide

The following information is intended to support animal-study design. Actual protocols should be optimized for the specific model.
Administration Route Applicable Animals Reference Dose Dosing Frequency Notes
Tail Vein Injection Mouse/Rat 5–20 nmol/animal Once every 2–3 days Most commonly used route;
systemic distribution
Local Injection Mouse
(intratumoral, subcutaneous, etc.)		 1–5 nmol/site Once every 3–5 days Targets local tissues
Intraperitoneal Injection Mouse/Rat 5–20 nmol/animal Once every 2–3 days systemic distribution，
easy to perform
Inhalation Administration Mouse Evaluate as needed Evaluate as needed Targets the lungs
Oral Gavage Mouse/Rat Evaluate as needed Evaluate as needed Targets the intestine
(cholesterol promotes intestinal enrichment)

For tail-vein injection in mice, the typical agomir dose is 5–20 nmol per animal. Because antagomir must competitively inhibit endogenous miRNA, its dose is generally higher (10–30 nmol per animal). A preliminary dose-response study is recommended.

Applications

Covering in vivo miRNA functional validation, disease models, and preclinical drug development

In Vivo miRNA Functional Validation

Administer agomir/antagomir in animal models to observe target-gene changes and overall phenotypes, completing the research loop from in vitro discovery to in vivo validation.

Cancer and Metabolic Disease Research

Use agomir to supplement tumor-suppressive miRNAs and antagomir to inhibit oncogenic miRNAs; also applicable to models of diabetes, obesity, fatty liver disease, and related conditions.

Neurodegenerative Disease Research

Target the central nervous system through intracerebroventricular injection or intranasal administration to validate miRNA functions in Alzheimer's disease, Parkinson's disease, and related disorders.

Preclinical Development of miRNA Therapeutics

Generate in vivo efficacy, PK/PD, tissue-distribution, and safety data. Modification designs and dosing strategies can be carried forward into subsequent drug development.

Frequently Asked Questions

Questions you may have about agomir/antagomir synthesis and in vivo applications
What is the difference between agomir and mimic, and how should I choose?
Agomir is a chemically modified version of mimic designed specifically for in vivo experiments. Mimic requires a transfection reagent and is limited to in vitro use, whereas agomir incorporates cholesterol, PS, and 2'-OMe modifications, requires no transfection reagent, extends the serum half-life to several days, and can remain effective for 1–5 weeks after a single injection. Use mimic for in vitro studies and agomir for in vivo studies; the same distinction applies to antagomir versus inhibitor.
What is the purpose of each of the three modifications?
  • 2'-O-methyl (2'-OMe):Provides resistance to nuclease degradation, improves target affinity, and reduces immunogenicity
  • Phosphorothioate (PS):Provides resistance to exonuclease degradation and extends the in vivo half-life
  • Cholesterol conjugation:Promotes cellular uptake and enrichment in tissues such as the liver and intestine
How should the dose and dosing frequency be determined?
For tail-vein injection in mice, administer agomir at 5–20 nmol per animal once every 2–3 days for 1–5 weeks. Because antagomir must competitively inhibit endogenous miRNA, its dose is generally higher, approximately 10–30 nmol per animal. A preliminary dose-response study is recommended.
How can in vivo effectiveness be verified?
  • Target-tissue enrichment:Collect target tissues 48–72 hours after injection and assess oligonucleotide distribution by qPCR
  • Target-gene changes:After agomir administration, target-gene mRNA/protein levels should decrease; after antagomir administration, they should increase;
  • Phenotype observation:Observe phenotypes such as tumor volume and metabolic indicators;
  • Include an NC control group with the same modification pattern and specification to exclude nonspecific effects.
Can the NC be shared with the NC used for mimic/inhibitor?
No. The strand format, modification design, and in vivo/in vitro experimental conditions differ. The NC must be matched to the corresponding experimental group.
Cholesterol modification causes preferential liver enrichment. What should I do for non-hepatic target tissues?
Cholesterol conjugation naturally promotes enrichment in the liver and intestine. For liver or intestinal targets, intravenous or intraperitoneal injection can be used directly. For other tissues such as the brain, muscle, or tumors, local administration (for example, intratumoral, intracerebroventricular, or intramuscular injection) is recommended to achieve an effective concentration in the target tissue.
How should the product be stored and dissolved?
Reconstitute with sterile PBS or normal saline. If dissolution is incomplete, briefly incubate at 37°C. Store the lyophilized powder at -20°C, protected from light, for 2–3 years. After reconstitution, aliquot and store at -20°C for long-term use, avoiding repeated freeze-thaw cycles. Maintain RNase-free conditions throughout.

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