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!
On this page: Oligonucleotide Modifications | Available Labels | Additional Resources | Other Custom Services
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.
Type | Label | Applications |
Enzyme | Horseradish Peroxidase (HRP) | HRP-oligos requires substrates for detection, such as TMB or Amplite® Red. It can be used in in situ hybridization, dot blots, cellular localization and non-radioactive immunoassays. |
Alkaline Phosphatase (AP) | AP-oligos require substrates for detection, such as FDP or MUP. It can be used in in situ hybridization, dot blots, cellular localization and non-radioactive immunoassays. | |
Other Tags | Biotin | Biotin-streptavidin detection system can be used in oligonucleotide labeling, in situ hybridization, blot hybridization, matrix binding, cellular localization, genomic hybridization, affinity binding and purification. |
Digoxigenin (DIG) | DIG binds tightly and with high affinity to anti-DNP antibodies. It can be used in oligonucleotide labeling, in situ hybridization, blot hybridization, cellular localization, genomic hybridization, affinity binding and purification. | |
Dinitriphenyl (DNP) | DNP binds tightly and with high affinity to anti-DNP antibodies. It can be used in oligonucleotide labeling, in situ hybridization, blot hybridization, cellular localization, genomic hybridization, affinity binding and purification. | |
3' and 5' Modification | Amine-Modifiers | Addition of primary amino groups (-NH?) facilitates the attachment of various modifiers including non-fluorescent tags, enzymes, fluorescent dyes and quenchers. It can also be used to attach an oligonucleotide to a solid surface. |
Thiol-Modifiers | Addition of thiol groups (-SH) facilitates the attachment of various modifiers including non-fluorescent tags, enzymes, fluorescent dyes and quenchers. It can also be used to attach an oligonucleotide to a solid surface. | |
Alkyne-Modifiers | Addition of alkyne groups facilitates the attachment of various fluorescent and non-fluorescent modifiers via click-chemistry. | |
Phosphate-Modifiers | Addition of 3'-phosphate groups inhibits degradation by some nucleases or blocks elongation by DNA polymerases. Addition of 5'-phosphate groups to oligos allows for subsequent ligation by DNA ligases. |
Table 1. Fluorescent Labels for Oligo Labeling
Emission Color ▲ ▼ | Conjugate ▲ ▼ | Ex (nm) ▲ ▼ | Em (nm) ▲ ▼ | ε¹ ▲ ▼ | CF 260 nm² ▲ ▼ |
AMCA | 353 | 455 | 19,000 | 0.183 | |
EDANS | 336 | 455 | 5,900 | 0.34 | |
6-FAM | 494 | 521 | 75,000 | 0.255 | |
6-TET | 521 | 536 | 76,000 | 0.191 | |
6-JOE | 520 | 548 | 73,000 | 0.326 | |
6-HEX | 533 | 550 | 74,000 | 0.300 | |
Cy3 | 549 | 565 | 150,000 | 0.033 | |
Cy3.5 | 581 | 569 | 125,000 | 0.151 | |
6-TAMRA | 547 | 573 | 75,000 | 0.335 | |
6-TAMRAA CPG *1000 Å* | 547 | 573 | 75,000 | 0.335 |
- ε = Extinction coefficient (cm-1M-1) at their maximum absorption wavelength
- CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm (for oligos and nucleic acid labeling)
Table 2. AAT Bioquest Fluorescent Tide Fluor™ Dyes
Emission Color ▲ ▼ | Conjugate ▲ ▼ | Ex (nm) ▲ ▼ | Em (nm) ▲ ▼ | ε¹ ▲ ▼ | CF 260 nm² ▲ ▼ |
Tide Fluor™ 1 | 345 | 422 | 20,000 | 0.246 | |
Tide Fluor™ 2WS | 502 | 525 | 75,000 | 0.211 | |
Tide Fluor™ 2 | 500 | 527 | 75,000 | 0.288 | |
Tide Fluor™ 3WS | 555 | 565 | 150,000 | 0.079 | |
Tide Fluor™ 3 | 546 | 571 | 85,000 | 0.331 | |
Tide Fluor™ 4 | 590 | 618 | 90,000 | 0.489 | |
Tide Fluor™ 5WS | 649 | 664 | 250,000 | 0.023 | |
Tide Fluor™ 6WS | 676 | 695 | 220,000 | 0.111 | |
Tide Fluor™ 7WS | 749 | 775 | 275,000 | 0.009 | |
Tide Fluor™ 8WS | 775 | 807 | 250,000 | 0.103 |
- ε = Extinction coefficient (cm-1M-1) at their maximum absorption wavelength
- CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm (for oligos and nucleic acid labeling)
Table 3. AAT Bioquest Non-Fluorescent Dyes and Quenchers
Conjugate ▲ ▼ | Abs (nm) ▲ ▼ | ε¹ ▲ ▼ | CF 260 nm² ▲ ▼ |
3'-DABCYL CPG *500 Å* | 454 | 20,000 | 0.614 |
Tide Quencher™ 1 | 492 | 20,000 | 0.149 |
Tide Quencher™ 1 CPG *500 Å* | 492 | 20,000 | 0.149 |
Tide Quencher™ 1 CPG *1000 Å* | 492 | 20,000 | 0.149 |
Tide Quencher™ 2 | 516 | 55,000 | 0.100 |
Tide Quencher™ 2 CPG *500 Å* | 516 | 55,000 | 0.100 |
Tide Quencher™ 2 CPG *1000 Å* | 516 | 55,000 | 0.100 |
Tide Quencher™ 2WS | 516 | 55,000 | 1.296 |
Tide Quencher™ 3 | 573 | 55,000 | 0.085 |
Tide Quencher™ 3 CPG *500 Å* | 573 | 55,000 | 0.085 |
- ε = Extinction coefficient (cm-1M-1) at their maximum absorption wavelength
- CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm (for oligos and nucleic acid labeling)
Please contact us at info@aatbio.com to inquire about additional or custom labels.
Additional Resources
Table 4. Tide Fluor™ equivalents of common dyes
If you are using ▲ ▼ | Try this Tide Fluor™ dye ▲ ▼ |
EDANS | Tide Fluor™ 1 (TF1) |
FAM, FITC, Alexa Fluor® 488 | Tide Fluor™ 2 (TF2) |
Alexa Fluor® 488 | Tide Fluor™ 2WS (TF2WS) |
Cy3®, Alexa Fluor® 555 | Tide Fluor™ 3 (TF3) |
Cy3®, Alexa Fluor® 555 | Tide Fluor™ 3WS (TF3WS) |
ROX, Texas Red®, Alexa Fluor® 594 | Tide Fluor™ 4 (TF4) |
Cy5®, Alexa Fluor® 647 | Tide Fluor™ 5WS (TF5WS) |
Cy5.5®, IRDye® 700, Alexa Fluor® 680 | Tide Fluor™ 6WS (TF6WS) |
Cy7®, Alexa Fluor® 750 | Tide Fluor™ 7WS (TF7WS) |
IRDye® 800 | Tide Fluor™ 8WS (TF8WS) |
Table 5. Tide Quencher™ equivalents of common dyes
If you are using ▲ ▼ | Try this Tide Quencher™ dye ▲ ▼ |
DABCYL, BHQ®-0, QSY®35 | Tide Quencher™ 1 (TQ1) |
BHQ®-1, QXL™ 520, Q®35 | Tide Quencher™ 2 (TQ2) or Tide Quencher™ 2WS (TQ2WS) |
BHQ®-2 | Tide Quencher™ 3 (TQ3) or Tide Quencher™ 3WS (TQ3WS) |
BHQ®-3, QSY®7, QSY®9 | Tide Quencher™ 4 (TQ4) or Tide Quencher™ 4WS (TQ4WS) |
QSY®21 | Tide Quencher™ 5 (TQ5) or Tide Quencher™ 5WS (TQ5WS) |
IRDye® QC-1 | Tide Quencher™ 6WS (TQ6WS) |
IRDye® QC-1 | Tide Quencher™ 7WS (TQ7WS) |
Table 6. Recommended FRET pairs for developing FRET oligonucleotides
Donor \ Acceptor ▲ ▼ | DABCYL ▲ ▼ | TQ1 ▲ ▼ | TQ2 ▲ ▼ | TQ3 ▲ ▼ | TQ4 ▲ ▼ | TQ5 ▲ ▼ | TQ6 ▲ ▼ | TQ7 ▲ ▼ |
EDANS | +++ | +++ | + | - | - | - | - | - |
MCA | +++ | +++ | + | - | - | - | - | - |
Tide Fluor™ 1 | +++ | +++ | + | - | - | - | - | - |
FAM FITC | + | + | +++ | + | - | - | - | - |
Cy2® Tide Fluor™ 2 | + | + | +++ | + | - | - | - | - |
HEX JOE TET | - | - | + | +++ | + | - | - | - |
Cy3® TAMRA Tide Fluor™ 3 | - | - | + | +++ | + | - | - | - |
ROX Texas Red® | - | - | - | + | +++ | + | - | - |
Tide Fluor™ 4 | - | - | - | + | +++ | + | - | - |
Cy5® Tide Fluor™ 5 | - | - | - | - | + | +++ | + | - |
Optimal choice
Acceptable to use
Not recommended to use