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Epigenetic Modified Base Oligonucleotides

Custom DNA and RNA oligonucleotides incorporating 5mC, 5hmC, 5fC, 5caC, 5hmU, m6dA/m6A, zebularine and specialty base analogs for methylation analysis, DNA repair, protein-binding studies and assay development.

45+ Years of Expertise ISO 9001:2015 / ISO13485:2016 5mC • 5hmC • 5fC • 5caC 8-oxoG • Inosine • dU • BrdU DNA/RNA Oligos • Probes • Standards

Synthetic Controls for Epigenetic Research

Bio-Synthesis manufactures custom oligonucleotides containing epigenetic base modifications and nucleobase analogs for methylation research, DNA repair studies, transcription regulation analysis, protein-binding assays, sequencing controls and assay development.

Modified bases can be incorporated into DNA oligos, RNA oligos, primers, probes, synthetic controls and reference standards. Our team can help evaluate sequence context, analog placement, synthesis compatibility, purification approach and analytical QC requirements.

Common programs include bisulfite sequencing controls, methylation-sensitive PCR controls, CpG methylation models, DNA repair substrates, protein-DNA binding substrates and NGS or qPCR assay standards.

Epigenetic Base Analog Oligo Design
Defined positionModified baseSynthetic control

Choose Modified Bases by Category

Use the tabs to compare modified-base categories, biological applications and design considerations without duplicating a separate reference table.

Cytosine Epigenetic Marks at a Glance

methylation models
bisulfite / PCR controls
CpG position
identity + purity
Category Modification Description / Application Code
Epigenetic 5-Carboxy dC 5-carboxy-2′-deoxycytidine (5-caC); TET pathway, oxidation controls and antibody validation. [5-ca-dC]
Epigenetic 5-formyl dC 5-formyl-2′-deoxycytidine (5-fC); intermediate in active demethylation and standard curves. [5-for-dC]
Epigenetic 5-hm dC 5-hydroxymethyl-2′-deoxycytidine (5-hmC); oxidative demethylation studies and antibody calibration. [5hmdC]
Epigenetic 5-methyl deoxycytosine 5-methyl-2′-deoxycytidine (5-mC); methylation controls, enzyme assays and qPCR standards. [5mdC]
RNA Epigenetic 5-methyl-Cytosine (RNA) 5-methyl-cytidine (5-mrC); RNA methylation biology and reader assays. [5mrC]

DNA Damage, Repair & Uracil/Thymine Analogs at a Glance

Best for
repair substrates
Common use
lesion controls
Design focus
lesion position
QC focus
sequence + mass
Category Analog Description / Application Code
Uracil / Thymine 5-Hydroxymethyl-dU 5-hmU (deoxyuridine); oxidative deamination models and antibody controls. [5hmdU]
Uracil / Thymine 5-formyl-dU 5-fU (deoxyuridine); damage/repair studies and calibration standards. [5for-dU]
DNA Damage 8-oxo-dG 8-oxoguanine lesion analog; DNA damage/repair and oxidative stress assays. [8oxo-dG]
DNA Repair Deoxyuridine Uracil-DNA glycosylase studies, deamination models and repair assay controls. dU
DNA Repair Abasic Site Models AP-site repair, polymerase bypass and lesion studies using stable abasic-site models. dSpacer

Wobble and Pairing Analogs at a Glance

Best for
pairing control
Common use
degenerate sites
Design focus
mismatch tolerance
QC focus
purity profile
Category Analog Typical Use Design Note
Wobble Pairing Inosine Wobble pairing, degenerate primers and mixed-template recognition Often used when broad base-pair tolerance is needed.
Universal Base Universal Base Universal pairing sites and variable-sequence regions May lower duplex stability; validate assay performance.
Pairing Analog 2,6-Diaminopurine Stability tuning and altered hydrogen-bonding studies Can increase A:T-like pairing strength in selected designs.
Artificial Pairing Iso-dG / Iso-dC Artificial base-pair and orthogonal pairing studies Best reviewed as a custom development project.

Adenine & Specialty Analogs at a Glance

Best for
RNA/DNA epigenetics
Common use
probes + controls
Design focus
function + placement
QC focus
custom release
Category Analog Description / Application Code
Adenine Epigenetic N6-Methyl dA (m6dA) N6-methyl-2′-deoxyadenosine; epigenetic adenine marks and enzyme validation. [m6dA]
RNA Epigenetic N6-Methyl rA (m6A) N6-methyl-adenosine; RNA methylation pathway and reader/writer assays. [m6A]
DNMT Tool rZebularine Ribo-zebularine; DNMT inhibitor analog and control studies. [rZ]
DNMT Tool Zebularine — deoxy-5-methyl Deoxy-zebularine (5-methyl); DNMT/repair pathway tools. [dZ-5me]
Fluorescent 2-Aminopurine Fluorescent adenine analog for structure/function studies and monitoring base stacking. [2AP]
Base Analog 7-deaza-A / 7-deaza-G Base analogs lacking N7 for structure probing and polymerase studies. [7dz-A]/[7dz-G]

Choose Modified Bases Around the Biological Question

Epigenetic and base analog oligos are most useful when the modification is selected around the assay mechanism, biological model and detection platform.

Common modified bases for methylation and hydroxymethylation assay controls.

Recommended Bases

5mC, 5hmC, 5fC and 5caC for methylation-state modeling.

Typical Uses

Bisulfite sequencing controls, MSP/qPCR controls and CpG methylation standards.

Design Focus

Define CpG position, strand orientation, amplicon region and control concentration.

Modified base substrates for lesion, repair and polymerase studies.

Recommended Bases

8-oxoG, dU, abasic-site models and lesion analogs.

Typical Uses

Base-excision repair, glycosylase assays, lesion bypass and damage-response studies.

Design Focus

Place lesions at defined positions and select duplex, hairpin or probe formats

Defined modified-base oligos for protein-DNA and protein-RNA interaction studies.

Recommended Bases

5mC, 5hmC, halogenated bases, fluorescent bases and affinity-tagged analogs.

Typical Uses

EMSA, pull-down, transcription-factor binding, methyl-binding protein assays.

Design Focus

Preserve binding motif, spacing, duplex context and detection handle placement.

Synthetic reference standards for sequencing, PCR and assay validation.

Recommended Bases

ssDNA, dsDNA, primers, probes, amplicon controls and spike-in standards.

Typical Uses

NGS controls, qPCR controls, methylation panels and assay calibration.

Design Focus

Match target region, modification state, concentration, purification and QC package.

Oligo Formats for Modified Base Incorporation

Modified bases can be designed into multiple oligonucleotide formats depending on your assay and downstream readout.

DNA

DNA Oligos

Position-specific modified-base DNA oligos for methylation, repair and binding studies.

RNA

RNA Oligos

RNA analog-containing oligos for epitranscriptomic and RNA-protein studies when compatible.

Pr

Primers & Probes

Modified-base primers, probes and assay oligos for PCR, qPCR and hybridization workflows.

Std

Controls & Standards

Synthetic standards, spike-ins and reference oligos for sequencing and assay validation.

Workflow for Epigenetic Modified Base Oligos

A successful modified-base oligo project connects the biological question with sequence design, analog placement, synthesis compatibility, purification and analytical QC.

01
Modification Selection

Select methylated, oxidized, lesion, wobble or specialty base analogs.

02
Sequence Design

Define base position, strand, duplex context, assay region and format.

03
Synthesis

Incorporate modified bases using compatible solid-phase oligo chemistry.

04
Purification

Use desalting, HPLC, PAGE or project-specific purification.

05
QC Verification

Confirm purity and identity using analytical methods appropriate for the construct.

06
Delivery

Provide final oligo, documentation, concentration and packaging format.

QC Strategy for Modified Base Oligos

Bio-Synthesis supports analytical characterization strategies for modified-base oligonucleotides using methods that evaluate purity, identity, sequence-specific requirements and final release attributes.

Analytical Control Matrix

Modified bases can affect chromatography, ionization, stability and assay performance. QC should be selected around the sequence, modification type and final use.

HPLC / UPLC

Purity assessment and method-specific chromatographic profile.

LC-MS

Mass identity confirmation where compatible with sequence and modification.

PAGE / CE

Size and purity review for selected oligo lengths and formats.

Documentation

CoA, concentration, yield and project-specific release information.

Sequence Context

Some analogs require special placement and synthesis review.

Duplex Controls

Complementary strand, annealing and duplex format available when needed.

Assay Readiness

Optional packaging, plates, concentration normalization and reference standards.

Purity
Identity
Concentration
Format
Documentation

Quality Support for Modified Base Oligo Programs

Modified-base oligos require controlled synthesis, careful purification and analytical release methods matched to the modification and application.

QMS

Delivery-Modified ISO-Supported Modified Base Oligo Platform

Bio-Synthesis supports custom synthesis, conjugation, purification, analytical characterization and documentation for delivery-enabled oligonucleotide programs.

ISO 9001:2015 Quality management system
ISO 13485:2016 Medical-device quality framework
Analytical QC HPLC/UPLC, LC-MS, PAGE and CoA
Custom Programs Confidential analog, sequence and assay-support workflows

FAQ

Can modified bases be placed at a defined position?
Yes. Many epigenetic and specialty base analogs can be incorporated at defined internal or terminal positions using custom solid-phase oligonucleotide synthesis, depending on sequence and chemistry compatibility.
Which modified base should I choose for methylation studies?
5mC is commonly used for methylated DNA controls, while 5hmC, 5fC and 5caC are used to model oxidized methylcytosine states and active demethylation pathway intermediates.
What QC is recommended?
Typical QC may include HPLC or UPLC purity, LC-MS identity where compatible, PAGE or CE purity review and project-specific documentation.
Can you make duplex controls?
Yes. Bio-Synthesis can provide modified strand, complementary strand and annealed duplex formats depending on your application and analytical requirements.
Can these be used as sequencing controls?
 Yes. Modified-base oligos can be designed as spike-ins, methylation controls, amplicon controls or synthetic standards for sequencing and assay validation.
What information is needed for a quote?
 Provide sequence, modification name and position, oligo format, scale, purification preference, QC requirements, duplex or single-strand format and application details.

Information Helpful for Modified Base Oligo Quotes

Sequence
5′→3′ sequence
Base
5mC, 5hmC, 8-oxoG, etc.
Position
internal or terminal site
Format
ssDNA, duplex, probe
Scale
nmol, µmol, mg
QC
HPLC, LC-MS, PAGE

Need a position-specific epigenetic or modified-base oligo?

Share your sequence, modified base, target position, oligo format, scale, purification and QC requirements. Bio-Synthesis can help evaluate synthesis compatibility and build a practical modified-base oligo workflow around your application.
5mC

Modification Review

Evaluate base analog, position, oligo length, duplex context and purification strategy.

5mC 5hmC 8-oxoG dU
QC

Release Package

HPLC/UPLC, LC-MS, PAGE, CoA, concentration and custom documentation support.

HPLC LC-MS PAGE CoA

Recommended Reading & Literature References

Use this section to support scientific credibility while keeping the page focused on modified-base design, synthesis and analytical verification.

  1. Kriaucionis S, Heintz N. The nuclear DNA base 5-hydroxymethylcytosine is present in Purkinje neurons and the brain. Science. 2009.
  2. Tahiliani M, et al. Conversion of 5-methylcytosine to 5-hydroxymethylcytosine in mammalian DNA by MLL partner TET1. Science. 2009.
  3. He YF, et al. Tet-mediated formation of 5-carboxylcytosine and its excision by TDG in mammalian DNA. Science. 2011.
  4. Shen L, Song CX, He C, Zhang Y. Mechanism and function of oxidative reversal of DNA and RNA methylation. Annual Review of Biochemistry. 2014.
  5. Cadet J, Douki T, Ravanat JL. Oxidatively generated damage to cellular DNA by UVB and UVA radiation. Photochemical & Photobiological Sciences. 2015.

Suggested page note:Literature references are provided for scientific background. Final modified-base oligonucleotide design should be evaluated within the sequence, modification position, synthesis scale, purification method, analytical QC and application model.

Why Choose Bio-Synthesis

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