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Custom Oligonucleotide Labeling
AAT Bioquest offers a wide range of modifications for DNA and RNA oligonucleotides, including fluorescent reporters, quencher labels, hapten modifications, as well as, amine and thiol functional linkers. Our custom services are designed to meet your specifications with stringent quality control and quick turnaround, to supply scientists with the necessary tools to satisfy even the most challenging of applications. Several applications in which our molecular biology tools can be successfully employed include fluorescence in situ hybridization (FISH), blotting assays, cell trafficking, intracellular localization, affinity purification, PCR, microarrays and sequencing.
Guaranteed quality
Affordable price tiers that work with your budget
Scalable service with minimum order of 250 nmole
Quick order fulfillment modified oligonucleotides delivered in 3-5 business days*
Oligonucleotides for modification must be supplied by the inquirer, AAT Bioquest does not custom manufacture any oligonucleotides. Contact us for a quote today, and let our highly motivated and experienced team of scientists work for you!
Oligonucleotide Modifications
Modified oligonucleotides are utilized in a wide range of applications spanning the fields of biotechnology, molecular biology, diagnosis and drug discovery. Depending upon the coupled moiety or reporter molecule, modified oligonucleotides can be used to provide a particular reactivity linking an oligonucleotide either to another molecule or desired surface, or can be modified to enhance visualizaton. Common modifications include biotin, digoxigenin, dinitriphenyl, amino-modifiers, alkyne modifiers, phosphate modifiers, fluorescent reporters and quencher labels.
Biotin-modified oligonucleotides, in particular, bind tightly and with high affinity to streptavidin. The streptavidin can be conjugated to a reporter molecule, such as a fluorophore or enzyme, and together they can been used in a variety of biological assays and affinity purification applications. Biotinylated oligonucleotides can also be used as probes or primers in either in vivo or in vitro applications. In PCR, the addition of 3'-phosphate groups block elongation, while in functional assays the incorporation of reactive moieties facilitate the covalent linking of nonradioactive labels such as enzymes. Several enzymes, such as horseradish peroxidase, are compatible with standard hybridization conditions, and allow detection by a number of endpoints including absorbance, fluorescence and luminescence.
Oligonucleotides can also be fluorescently modified. Oligos bearing fluorescent tags have been widely used as probes in automated DNA sequencing, FISH and PCR product detection. Dual-modified oligonucleotides with a fluorophore and a quencher at their 5' and 3' ends, respectively, have been used in all major types of fluorescence imaging including fluorescence resonance energy transfer (FRET) and quantitative PCR. In the presence of a complementary sequence, these probes commonly referred to as molecular beacons, unfold and hybridize to the target. The resulting conformational change produces sufficient displacement of the fluorophore from its respective quencher, thereby restoring fluorescence. In quantitative PCR, molecular beacons bind to the amplified target following each cycle of amplification and the resulting signal is proportional to the amount of template. Common fluorophore/quencher pairs include EDANS/DABCYL and Tide Fluor™-Tide Quencher™ pairs.
Available Labels
Picking the correct label can be challenging. Let our experts help simplify the process! Contact us by email or phone (1-(800)-990-8053) for a consultation and let us work with you to pick the best label to suit your specific needs. And don't fret if you can't find a modification you need on our website, AAT Bioquest offers several modifications that are not listed in our online catalog.
Please contact us at info@aatbio.com to inquire about additional or custom labels.
Additional Resources

Document: 01.0053.211015r1
Last updated Fri Oct 03 2025

Custom Oligonucleotide Labeling