Oligo Modifications—Standard and Custom

We partner every day with you, our customers, to find unique solutions that match your needs and applications. The tabs here show the most commonly requested modifications. Our scientists can also include modifications sythesized by you into our oligos. Please contact our Customer Service representatives at GenomicsServices@eurofins.com for more info.

We offer a wide variety of modifications for both DNA and RNA oligos. While all the modifications listed here are permitted for oligos synthesized at 200 nmole synthesis scale and delivered in tubes, several modifications are available at other synthesis scales as well.

Independent of the intended application, some modifications require further purification before being shipped out to you. Each order editor has a dropdown list of available modifications that you can order. Alternately, you can type in the designator in the sequence to order the same; note that the designators are case sensitive. Additional information on the availabel modifications, the designator used for ordering the same, and the chemical structure can be found by following the hyperlink in the tables listing the modifications in the tabs.

The modifications have been categorized based on their features. Predefined Dye–Quencher combinations are available when you order dual-labeled or MGB probes. Furthermore, dinucleotide DNA base combinations are also listed in the siMAX^TM siRNA order editor.  

Do not see a modification you want? Contact us. We may be able to accommodate non-standard modifications.

Modifications Available for Custom Oligonucleotides delivered in Tubes

Do not see a modification you want? Contact us. We may be able to accommodate non-standard modifications.

Fluorescent Dyes

Fluorophore	Designator	5'	Int	3'	Max Abs (nm)	Max Em (nm)	Extinction coefficient (M-1cm–1)	QY††
Alexa Fluor 405	[Alexa405]	✓	✓	✓	401	421	34,000
Alexa Fluor 350	[Alexa350]	✓	✓	✓	346	424	19,000
CF405SN	[CF405SN]	✓	✓	✓	404	431	33,000
Tide Fluor 1	[TF1]	✓	✓	✓	341	447		0.95
ATTO 390	[ATTO390]	✓	✓	✓	390	479	24,000
5-FAM	[5FAM]	✓			492	518
Alexa Fluor 488	[Alexa488]	✓	✓	✓	496	519	71,000	0.92
Fluorescein	[FL]	✓	✓		495	520	83,000	0.9
6-FAM	[FAM]	✓		✓	495	521	75,000	0.9
Fluorescein dT	[FLUdT]	✓	✓		494	522	75,000	0.9
Tide Fluor 2	[TF2]	✓	✓	✓	499	522		0.9
ATTO 488	[ATTO488]	✓	✓	✓	501	523	90,000	0.8
Oregon Green 488	[OG488]	✓	✓	✓	496	524	76,000
TET	[TET]	✓			519	539	86,000	0.9
CAL Fluor Gold 540	[CalFluor540]	✓			522	543	81,100
JOE	[JOE]	✓	✓	✓	520	548	73,000	0.7
Yakima Yellow	[YAKYE]	✓			524	551	83,800
Alexa Fluor 532	[Alexa532]	✓	✓	✓	532	553	81,000	0.61
ATTO 532	[ATTO532]	✓	✓	✓	532	553	115,000	0.9
HEX	[HEX]	✓			537	556	96,000	0.7
Alexa Fluor 555	[Alexa555]	✓	✓	✓	555	565	150,000	0.1
Alexa Fluor 546	[Alexa546]	✓	✓	✓	556	573	104,000	0.79
ATTO 550	[ATTO550]	✓	✓	✓	554	576	120,000	0.8
TAMRA dT	[TAMdT]	✓	✓		544	576	90,000
Tide Fluor 3	[TF3]	✓	✓	✓	554	578		0.86
TAMRA	[TAM]			✓	556	580	89,000	0.7
5-Tamra (ester)	[TMR5]	✓			557	583
CAL Fluor Red 590	[CalFluor590]	✓			569	591	79,000
ATTO 565	[ATTO565]	✓	✓	✓	563	592	120,000	0.9
ROX	[ROX]	✓	✓	✓	575	602	82,000
Alexa Fluor 568	[Alexa568]	✓	✓	✓	578	603	91,000	0.69
Texas Red	[TxRed]	✓	✓	✓	583	603	116,000
Cyanine3.5 dye	[Cy35]	✓	✓		591	604	116,000	0.15
CAL Fluor Red 610	[CalFluor610]	✓			590	610	108,000
Tide Fluor 4	[TF4]	✓	✓	✓	588	610		0.7
Alexa Fluor 594	[Alexa594]	✓	✓	✓	590	617	73,000	0.66
ATTO 590	[ATTO590]	✓	✓	✓	594	624	120,000	0.8
CAL Fluor 635	[CalFluor635]	✓			616	637	36,500
Alexa Fluor 633	[Alexa633]	✓	✓	✓	632	647	239,000
ATTO 633	[ATTO633]	✓	✓	✓	629	657	130,000	0.64
Cyanine5 dye	[Cy5]	✓			646	662	250,000	0.3
Alexa Fluor 647	[Alexa647]	✓	✓	✓	650	665	239,000	0.33
ATTO 647N	[ATTO647N]	✓	✓	✓	644	669	150,000	0.65
Tide Fluor 5	[TF5]	✓	✓	✓	656	670		0.27
ATTO 655	[ATTO655]	✓	✓	✓	663	684	125,000	0.3
Alexa Fluor 660	[Alexa660]	✓	✓	✓	663	690	132,000	0.37
Alexa Fluor 680	[Alexa680]	✓	✓	✓	679	702	184,000	0.36
Tide Fluor 6	[TF6]	✓	✓	✓	686	702		0.23
Cyanine5.5 dye	[Cy55]	✓			688	707	209,000	0.3
ATTO 700	[ATTO700]	✓	✓	✓	700	719	120,000	0.25
Alexa Fluor 700	[Alexa700]	✓	✓	✓	702	723	192,000	0.25
ATTO 740	[ATTO740]	✓	✓	✓	740	764	120,000	0.1
Alexa Fluor 750	[Alexa750]	✓	✓	✓	749	775	240,000	0.12
Tide Fluor 7	[TF7]	✓	✓	✓	756	775		0.12
Tide Fluor 8	[TF8]	✓	✓	✓	787	808

†† QY (quantum yield) is a calculated ratio between the number of photons emitted and the number of photons absorbed. The most desirable QY for DLP purposes approaches 1.

Mixed/Degenerate Bases

MIXED BASES	Designator	5'	Int	3'	Composition
N (any base)	N	✓	✓	✓	N = (A, 25%; C, 25%; G, 25%; T, 25%)
B (not A)	B	✓	✓	✓	B = (C, 33.3%; G, 33.3%; T, 33.3%)
D (not C)	D	✓	✓	✓	D = (A-33.3%, G-33.3%, T-33.3%)
H (not G bases)	H	✓	✓	✓	H = (A, 33.3%; C, 33.3%; T, 33.3%)
V (not T)	V	✓	✓	✓	V = (A, 33.3%; C, 33.3%; G, 33.3%)
K (G and T)	K	✓	✓	✓	K = (G, 50%; T, 50%)
M (A and C)	M	✓	✓	✓	M = (A, 50%; C, 50%)
R (purines)	R	✓	✓	✓	R = (A, 50%; G, 50%)
S (strong bonds)	S	✓	✓	✓	S = (C, 50%; G, 50%)
W (weak bonds)	W	✓	✓	✓	W = (A, 50%; T, 50%)
Y (pyrimidines)	Y	✓	✓	✓	Y = (C, 50%; T, 50%)

Attachment Mods

Attachment Mods	Designator	5'	Int	3'	Structure
Amino Modifier C12	[AmC12]	✓			link
Amino Modifier C3	[AmC3]	✓		✓	link
Amino Modifier C6	[AmC6]	✓			link
Amino Modifier C6-dT	[AmC6dT]	✓	✓		link
Amino Modifier C7	[AmC7]		✓	✓	link
Azide	[Azide]	✓	✓	✓
Hexynyl	[Hexynyl]	✓
Uni-Link AminoModifier	[AmUni]	✓	✓		link
i3Thiodl	[i3Thiodl]	✓	✓
Thiol Modifier C6 S-S	[ThiolC6]	✓	✓		link
Thiol Mod C3 S-S	[ThiolC3]			✓	link
Phosphate	[PHO]	✓		✓	link

Non-fluor labels

Non-flour labels	Code	5'	Int	3'	Structure
Biotin	[BIO]	✓			link
Biotin-dT	[BIOdT]	✓	✓		link
Biotin-ON	[BioON]	✓	✓		link
Biotin-TEG (5' or 3')	[BIOTEG]	✓		✓	link
Biotin-TEG (internal)	[BIOTEGi]		✓		link
Digoxigenin (ester)	[DIG]	✓	✓	✓	link
DNP (2,4-dinitrophenyl)	[DNP]	✓	✓		link

Modified Bases, Spacers, Miscellaneous

Modified Bases, Spacers, Misc	Code	5'	Int	3'	Structure
23ddC	[23ddC]			✓
5-Methyl dC	[5MedC]	✓	✓	✓	link
Acrydite	[5Acrd]	✓			link
Cholesteryl-TEG	[CholTEG]	✓	✓
Cholesteryl-TEG	[Chol]			✓
5' Dabcyl-dT	[5DabsyldT] or [5DabcyldT]	✓	✓		link
deoxyInosine [I]	[I]	✓	✓		link
deoxyUridine [U]	[U]	✓	✓		link
dP + dK mixture	[dPdK]	✓	✓		link
dT-5' (reversed base)	[dTrev]			✓
pdC	[pdC]	✓	✓
pdU	[pdU]	✓	✓
Phosphorothioation (PTO Bond)A backbone modification)	*		✓		link
dSpacer	[Spd]	✓	✓		link
Spacer C18	[SP18]	✓	✓		link
Spacer C3	[SpC3]	✓	✓	✓	link
Spacer C9	[SpC9]	✓	✓		link
TINA	[TINA]	✓

Quenchers

Quencher	Code	Quenching range (nm)	5'	Int	3'	Max Abs (nm)	Extinction Coefficient (M-1cm–1)
BBQ650	[BBQ650]	550-720	✓		✓	650	33,000
BHQ1	[BHQ1]	480–580	✓		✓	534	34,000
BHQ1 dT	[BHQ1dT]	480–580	✓	✓		534	34,000
BHQ2	[BHQ2]	550–650	✓		✓	579	91,000
BHQ2 dT	[BHQ2dT]	550–650	✓	✓		579	91,000
Dabcyl dT	[DABdT]	400–550	✓	✓		478	32,000
TAMRA	[TAM]	500–600	✓		✓	557	91,000
Tide Quencher 1	[TQ1]	420–530			✓	510	20,000
Tide Quencher 2	[TQ2]	440–580			✓	531	21,000
Tide Quencher 3	[TQ3]	510–620			✓	598	22,000
Tide Quencher 5	[TQ5]	600–730			✓	680	24,000

Modifications available for custom oligonucleotides delivered in 96-well plates

Oligos delivered in plates, even those mixed or pooled, can contain a variety of widely-employed modifications. That list is below for your convenience. If your modification is not on the list, please contact Customer Service. We want to ensure that your research is enabled through whatever modification you may require.

Standard Modifications for Plate Oligos

Fluorescent labels

Fluorophore	Designator	5'	Int	3'	Max Abs (nm)	Max Em (nm)	Extinction coefficient (M-1cm–1	QY††
6-FAM	[FAM]	✓			495	521	75,000	0.9
HEX	[HEX]	✓			537	556	96,000	0.7
TAMRA	[TAM]			✓	556	580	89,000	0.7
TET	[TET]	✓			519	539	86,000	0.9
†† QY (quantum yield) is a calculated ratio between the number of photons emitted and the number of photons absorbed. The most desireable QY for DLP purposes approaches 1.

Mixed Bases

MIXED BASES	Designator	5'	Int	3'	Composition
N (any base)	N	✓	✓	✓	N = (A, 25%; C, 25%; G, 25%; T, 25%)
B (not A)	B	✓	✓	✓	B = (C, 33.3%; G, 33.3%; T, 33.3%)
D (not C)	D	✓	✓	✓	D = (A, 33.3%; G, 33.3%; T, 33.3%)
H (not G)	H	✓	✓	✓	H = (A, 33.3%; C, 33.3%; T, 33.3%)
V (not T)	V	✓	✓	✓	V = (A, 33.3%; C, 33.3%; G, 33.3%)
K (G and T)	K	✓	✓	✓	K = (G, 50%; T, 50%)
M (A and C)	M	✓	✓	✓	M = (A, 50%; C, 50%)
R (purines)	R	✓	✓	✓	R = (A, 50%; G, 50%)
S (strong bonds)	S	✓	✓	✓	S = (C, 50%; G, 50%)
W (weak bonds)	W	✓	✓	✓	W = (A, 50%; T, 50%)
Y (pyrimidines)	Y	✓	✓	✓	Y = (C, 50%; T, 50%)
Hand Mixed Wobbles	[%-%-%-%]	✓	✓	✓	% defines the mixture of bases

Modified Bases, Spacers, Misc

Modified Bases, Spacers, Misc	Code	5'	Int	3'	Structure
I	[I]	✓	✓	✓	link
U	[U]	✓	✓	✓	link
Spacer C3	[SpC3]	✓	✓	✓	link

Attachment Mods

Attachment Mods	Designator	5'	Int	3'	Structure
Amino Modifier C12	[AmC12]	✓			link
Amino Modifier C6	[AmC6]	✓			link
Amino Modifier C6-dT	[AmC6dT]		✓		link
Amino Modifier C7	[AmC7]			✓	link
Uni-Link AminoModifier	[AmUni]		✓		link
Phosphate	[PHO]	✓		✓	link

Non-flourescent labels

Non-flour labels	Designator	5'	Int	3'	Structure
Biotin	[BIO]	✓		✓	link
Biotin-dT	[BIOdT]	✓	✓		link
Biotin-TEG	[BIOTEG]	✓	✓	✓	link

Regulated Environments

Our oligos are manufactured in our ISO 9001:2008 and ISO 13485:2003 certified facility in Louisville, Alabama. Eurofins Genomics quality management system is assurance that our oligos and other products and services are suitable for use in your cGMP, ASR, or QS regulation projects. Contact us at 1-800-688-2248 to discuss high throughput modified oligos for your FDA or CLIA regulated projects.

Modifications for RNA or RNA/DNA Chimeric in tubes

Fluors

Fluorophore	Designator	5'	Int	3'	Max Abs (nm)	Max Em (nm)	Extinction coefficient (M–1cm–1)	QY††
Cyanine5 dye	[Cy5]	✓			646	662	250,000	0.3
5-FAM	[5FAM]	✓			492	518
6-FAM	[FAM]	✓			495	521	75,000	0.9
HEX	[HEX]	✓			537	556	96,000	0.7
TET	[TET]	✓			519	539	86,000	0.9
†† QY (quantum yield) is a calculated ratio between the number of photons emitted and the number of photons absorbed. The most desireable QY for DLP purposes approaches 1.

Mixed Bases

MIXED BASES	Designator	5'	Int	3'	Composition
N (any base)	[N]	✓	✓	✓	N = (A, 25%; C, 25%; G, 25%; T, 25%)
B (not A)	[B]	✓	✓	✓	B = (C, 33.3%; G, 33.3%; T, 33.3%)
D (not C)	[D]	✓	✓	✓	D = (A, 33.3%; G, 33.3%; T, 33.3%)
H (not G)	[H]	✓	✓	✓	H = (A, 33.3%; C, 33.3%; T, 33.3%)
V (not T)	[V]	✓	✓	✓	V = (A, 33.3%; C, 33.3%; G, 33.3%)
K (G and T)	[K]	✓	✓	✓	K = (G, 50%; T, 50%)
M (A and C)	[M]	✓	✓	✓	M = (A, 50%; C, 50%)
R (purines)	[R]	✓	✓	✓	R = (A, 50%; G, 50%)
S (strong bonds)	[S]	✓	✓	✓	S = (C, 50%; G, 50%)
W (weak bonds)	[W]	✓	✓	✓	W = (A, 50%; T, 50%)
Y (pyrimidines)	[Y]	✓	✓	✓	Y = (C, 50%; T, 50%)

Attachment Mods

Attachment Mods	Designator	5'	Int	3'	Structure
Amino Modifier C6	[AmC6]	✓			link
Amino Modifier C6-dT	[AmC6dT]		✓		link
Amino Modifier C7	[AmC7]			✓	link
Phosphate	[PHO]	✓		✓	link

Non-flour labels

Non-flour labels	Designator	5'	Int	3'	Structure
Biotin-ON	[BioON]	✓	✓		link
Biotin-TEG (5' or 3')	[BIOTEG]	✓		✓	link
Biotin-TEG (internal)	[BIOTEGi]		✓		link
Cholesteryl-TEG (5' or Int)nternal)	[CholTEG]	✓	✓		link

Modified Bases, Spacers, Misc

Modified Bases, Spacers, Misc	Designator	5'	Int	3'	Structure
2'-O-Methyl-A	[2OMeA]	✓	✓	✓	link
2'-O-Methyl-C	[2OMeC]	✓	✓	✓	link
2'-O-Methyl-G	[2OMeG]	✓	✓	✓	link
2'-O-Methyl-U	[2OMeU]	✓	✓	✓	link
2'-Fluoro-G	[2FlG]	✓	✓		link
I	[I]	✓	✓		link
U	[U]	✓	✓		link

Non-Standard Modifications

Eurofins Genomics offers many more modifications in addition to the standard portfolio, which is covered in the previous tabs. Non-standard modifications are amidites that we are experienced with using but are not regularly stocked in our inventory for cost reasons. Below is a list of common, non-standard modifications. If you do not see the modification that you are looking for, contact us! Our chemists are always up for a challenge.

Please note that these modifications may not be visible on the order pages. To request one, email GenomicsSupport@eurofins.com.

Attachment Mods

Amino, thiol, acrydite, and phosphate groups incorporated during synthesis allow post synthesis reactions for attaching a variety of labels or for coupling the oligo with other molecules.

Modifier [Legacy Designator]	Availability	Structure
3'-PT-Amino-Modifier C3 [AmC3-PT-Q]	3'
Amino Modifier C12 [AmC12]	5'
Amino Modifier C2 dT [AmC2-dT]	5', Internal
Amino Modifier C3 [AmC3]	5'
Amino Modifier C6 [AminoC6]	5'
Amino Modifier C6 dT [AmC6-dT]	5', Internal
Amino Modifier C7 [AmC7-Q]	3'
AminoC6 dC [AmC6-dC]	5', Internal	Image not available.
Phosphate [Phos]	5'
Phosphate [Phos-Q]	3'
Thiol Mod C3 S-S [ThiolC3]	3'
Thiol Modifier C6 S-S [ThiolC6]	5', Internal
Uni-Link AminoModifier [Am-Uni]	5', Internal

DNA Analogs

Molecules with similar structure to DNA often readily substitute in the DNA strand for a variety of experimental uses. Modifications in this category include inosine, uridine, wobbles, etc.

Modifier [Legacy Designator]	Availability	Structure
3-Nitropyrrole [NitPyr]	5', Internal
5-Nitroindole [5-NitIdl-Q]	3'
5-Nitroindole [5-NitIdl]	5', Internal
AP-dC [AP-dC]	5', Internal	Image not available.
dK [dK]	5', Internal
dP [dP-Q]	3'
dP [dP]	5', Internal
dP + dK mixture [dPdK]	5', Internal
deoxyInosine [I]	5', Internal
deoxyInosine [I-Q]	3'
deoxyUridine [U]	5', Internal
deoxyUridine [U-Q]	3'

Fluorophores

Fluorescent molecules offer a wide variety of applications requiring detection of hybridization including in situ probes, sequencing, and genotyping.

Modifier [Legacy Designator]	Availability	Structure
5-FAM [5-fam]	5'
6-Carboxyfluorescein [6Fl]	5', Internal
6-Carboxyrhodamine (ester) [CR6G]	5', 3', Internal
6-FAM [6-Fam-Q]	3'
6-FAM (standard) [6-FAM]	5'
6-Joe, SE (ester) [JOE]	5', 3', Internal
ATTO390 (ester) [ATTO390]	5', 3', Internal	Image not available.
ATTO488 (ester) [ATTO488]	5', 3', Internal	Image not available.
ATTO532 (ester) [ATTO532]	5', 3', Internal	Image not available.
ATTO550 (ester) [ATTO550]	5', 3', Internal	Image not available.
ATTO565 (ester) [ATTO565]	5', 3', Internal	Image not available.
ATTO590 (ester) [ATTO590]	5', 3', Internal	Image not available.
ATTO633 (ester) [ATTO633]	5', 3', Internal	Image not available.
ATTO647N (ester) [ATTO647N]	5', 3', Internal	Image not available.
ATTO655 (ester) [ATTO655]	5', 3', Internal	Image not available.
ATTO700 (ester) [ATTO700]	5', 3', Internal	Image not available.
ATTO740 (ester) [ATTO740]	5', 3', Internal	Image not available.
Alexa Fluor 350 (ester) [Alexa350]	5', 3', Internal
Alexa Fluor 488 (ester) [Alexa488]	5', 3', Internal
Alexa Fluor 532 (ester) [Alexa532]	5', 3', Internal
Alexa Fluor 546 (ester) [Alexa546]	5', 3', Internal
Alexa Fluor 555 (ester) [Alexa555]	5', 3', Internal	Image not available.
Alexa Fluor 568 (ester) [Alexa568]	5', 3', Internal
Alexa Fluor 594 (ester) [Alexa594]	5', 3', Internal
Alexa Fluor 633 (ester) [Alexa633]	5', 3', Internal	Image not available.
Alexa Fluor 647 (ester) [Alexa647]	5', 3', Internal	Image not available.
Alexa Fluor 660 (ester) [Alexa660]	5', 3', Internal	Image not available.
Alexa Fluor 680 (ester) [Alexa680]	5', 3', Internal	Image not available.
Alexa Fluor 700 (ester) [Alexa700]	5', 3', Internal	Image not available.
Alexa Fluor 750 (ester) [Alexa750]	5', 3', Internal	Image not available.
Cal Fluor Red 610	5'	Image not available.
Cyanine3 [Cyanine3]	5'
Cyanine3 (ester) [Cyanine3es]	3'	Image not available.
Cyanine3.5 [Cyanine35]	5', Internal
Cyanine3.5 (ester) [Cyanine35es]	3'	Image not available.
Cyanine5 [Cyanine5]	5'
Cyanine5 (ester) [Cyanine5es]	3'	Image not available.
Cyanine5.5 [Cyanine55]	5'
DY682 (replaces IRD700) [DY682]	5', 3'	Image not available.
DY782 (replaces IRD800) [DY782]	5'	Image not available.
Fluorescein [Fl]	5', Internal
Fluorescein-dT [Fl-dT]	5', Internal
HEX [5HEX]	5'
Oregon Green 488 (ester) [OrGre]	5', 3', Internal
ROX (ester) [ROX]	5', 3', Internal
TAMRA (STANDARD) [TAMRA]	5'
TAMRA (STANDARD) [Tamra-Q]	3'
TAMRA-dT [TAMdT]	5', Internal
TET [5TET]	5'
Tamra (ester) - 5-isomer [TMR-5]	5', 3', Internal
Texas Red-X (ester) [TxRed]	5', 3', Internal
Tide Fluor 1 [TF1]	5', 3', Internal	Image not available.
Tide Fluor 2 [TF2]	5', 3', Internal	Image not available.
Tide Fluor 3 [TF3]	5', 3', Internal	Image not available.
Tide Fluor 4 [TF4]	5', 3', Internal	Image not available.
Tide Fluor 5 [TF5]	5', 3', Internal	Image not available.
Tide Quencher 2 ester [TQ2es]	5', 3', Internal	Image not available.

Mixed Bases

Standard bases used in combination to create a base comprised of a mixture of 2-4 bases (e.g. A/C or A/C/G). This category includes IUB Wobbles and custom wobbles.

Modifier [Legacy Designator]	Availability	Structure
3' B Wobble (C+G+T) [B-Q]	3'
3' D Wobble (A+G+T) [D-Q]	3'
3' H Wobble (A+C+T) [H-Q]	3'
3' K Wobble (G+T) [K-Q]	3'
3' M Wobble (A+C) [M-Q]	3'
3' N Wobble (A+C+G+T) [N-Q]	3'
3' R Wobble (A+G) [R-Q]	3'
3' S Wobble (C+G) [S-Q]	3'
3' V Wobble (A+C+G) [V-Q]	3'
3' W Wobble (A+T) [W-Q]	3'
3' Y Wobble (C+T) [Y-Q]	3'
B Wobble (C+G+T) [B]	5', Internal
D Wobble (A+G+T) [D]	5', Internal
H Wobble (A+C+T) [H]	5', Internal
K Wobble (G+T) [K]	5', Internal
M Wobble (A+C) [M]	5', Internal
Mix-1 MG [Mix-1]	5', Internal	Image not available.
N Wobble (A+C+G+T) [N]	5', Internal
R Wobble (A+G) [R]	5', Internal
S Wobble (C+G) [S]	5', Internal
V Wobble (A+C+G) [V]	5', Internal
W Wobble (A+T) [W]	5', Internal
Wobble 10%A 20%G 70%T [10-00-20-70]	5', 3', Internal
Wobble 20%A 20%C 60%G [20-20-60-00]	5', 3', Internal
Wobble 20%A 20%C 60%T [20-20-00-60]	5', 3', Internal
Wobble 20%A 40%C 40%T [20-40-00-40]	5', 3', Internal
Wobble 20%A 80%G [20-0-80-0]	5', 3', Internal
Wobble 30%A 30%C 40%T [30-30-00-40]	5', 3', Internal
Wobble 30%A 70%G [30-0-70-0]	5', 3', Internal
Wobble 40%A 30%G 30%T [40-00-30-30]	5', 3', Internal
Wobble 40%A 40%G 20%T [40-00-40-20]	5', 3', Internal
Wobble 60%A 20%C 20%G [60-20-20-00]	5', 3', Internal
Wobble 60%A 20%G 20%T [60-00-20-20]	5', 3', Internal
Wobble 60%C 20%G 20%T [00-60-20-20]	5', 3', Internal
Wobble 70%A 20%C 10%T [70-20-00-10]	5', 3', Internal
Wobble 70%C 30%T [0-70-0-30]	5', 3', Internal
Wobble 80%A 20%C [80-20-00-00]	5', 3', Internal
Wobble 80%C 20%G [00-80-20-00]	5', 3', Internal
Wobble 80%C 20%T [00-80-00-20]	5', 3', Internal
Wobble 90%C 10%T [00-90-00-10]	5', 3', Internal
Y Wobble (C+T) [Y]	5', Internal

Quenchers

Quenchers are most commonly paired with specific fluorophores and are chosen based on their ability to absorb energy at the emission wavelength of the fluorophore.

Modifier [Legacy Designator]	Availability	Structure
5-Dabcyl [5-Dabcyl]	5'
BHQ1-dT [BHQ1-dT]	5', Internal
BHQ2-dT [BHQ2-dT]	5', Internal
Black Hole Quencher 1 [BHQ1]	5', Internal
Black Hole Quencher 1 [BHQ1a-Q]	3'
Black Hole Quencher 2 [BHQ2]	5', Internal
Black Hole Quencher 2 [BHQ2a-Q]	3'
Dabcyl (STANDARD) [Dabcyl-Q]	3'
Dabsyl-dT [Dab-dT]	5', Internal
QSY 7 (ester) [QSY7]	5', 3', Internal
Tide Quencher 1 [TQ1-Q]	3'	Image not available.
Tide Quencher 2 [TQ2-Q]	3'	Image not available.
Tide Quencher 3 [TQ3-Q]	3'	Image not available.
Tide Quencher 4 [TQ4-Q]	3'	Image not available.

Spacers

Spacers form a non-binding bridge between areas of an oligo. Among our offerings are C3 spacer which can substitute for an unknown base and Spacer 18 which introduces a hydrophobic area in an oligo.

Modifier [Legacy Designator]	Availability	Structure
Spacer 18 [Sp-C18]	5', Internal
Spacer 9 [Sp-9]	5', Internal
Spacer C3 [Sp-3-Q]	3'
Spacer C3 [Sp-3]	5', Internal
dSpacer [Sp-d]	5', Internal

Biotins

Biotin offers a variety of uses in research including assays in drug discovery, histological, and cytological applications and capture methods are based on the high affinity of biotin for avidin and streptavidin.

Modifier [Legacy Designator]	Availability	Structure
3'-Biotin [Biotin-Q]	3'	Image not available.
5'-Biotin [Biotin-5]	5'
Biotin PC (Photocleavable) [Bio-PC]	5'
Biotin-ON [Bio-ON]	5', Internal
Biotin-TEG (STANDARD) [BioTEG-Q]	3'
Biotin-TEG (STANDARD) [BioTEG]	5'
Biotin-TEG (internal) [BioTEGi]	Internal
Biotin-dT [Bio-dT]	5', Internal

Dual-labeled Probes

A selected grouping of highly popular Fluorophore/Quencher pairings for real-time/qPCR applications.

Modified Bases

Chemically modified bases can be used for structural studies and enhanced binding. This category includes Br-dU, 5-methyl dC, 5-iodo dU, 2-aminopurine, etc.

Modifier [Legacy Designator]	Availability	Structure
2-Aminopurine [2AmPur]	5', Internal
5-Bromo dU [5Br-dU-Q]	3'
5-Bromo-dC [5Br-dC]	5', Internal
5-Bromo-dU [5Br-dU]	5', Internal
5-Iodo-dU [5I-dU]	5', Internal
5-Methyl dC [5Me-dC]	5', Internal
5-Methyl-dC [5Me-dC-Q]	3'
O6-phenyl-dI [6phnl-dI]	5', Internal
Pyrrolo-dC [Pyrlo-dC]	5', Internal

RNA Analogs

RNA analogs are useful for creating the chimeric DNA/RNA oligos commonly used in anti-sense studies.

Modifier [Legacy Designator]	Availability	Structure
2'-Fluoro-A [2F-A]	5', Internal	Image not available.
2'-Fluoro-C [2F-C]	5', Internal	Image not available.
2'-Fluoro-G [2F-G]	5', Internal	Image not available.
2'-Fluoro-U [2F-U]	5', Internal	Image not available.
2'-O Methyl-A [2OMeA-Q]	3'
2'-O Methyl-C [2OMeC-Q]	3'
2'-O Methyl-G [2OMeG-Q]	3'
2'-O Methyl-U [2OMeU-Q]	3'
2'-O-Methyl-A [2OMeA]	5', Internal
2'-O-Methyl-C [2OMeC]	5', Internal
2'-O-Methyl-G [2OMeG]	5', Internal
2'-O-Methyl-U [2OMeU]	5', Internal
5'OH-Methyl-C [5HOMedC]	5', Internal	Image not available.
Pyrrolo-RNA-C [Pyrrolo-rC]	5', Internal	Image not available.
Ribo A [rA]	5', Internal	Image not available.
Ribo A [rA-Q]	3'	Image not available.
Ribo C [rC-Q]	3'	Image not available.
Ribo C [rC]	5', Internal	Image not available.
Ribo G [rG-Q]	3'	Image not available.
Ribo G [rG]	5', Internal	Image not available.
Ribo U [rU]	5', Internal	Image not available.
Ribo U [rU-Q]	3'	Image not available.
Ribo-8OxrG [8Ox-rG]	5', Internal	Image not available.

Miscellaneous

Miscellaneous modifications include phosphorothioate backbone modification, digoxigenin labeling, modified bases to prevent extension of the 3' terminus, cholesterol for cell delivery, puromycin (a tRNA mimc), etc.

Modifier [Legacy Designator]	Availability	Structure
2'3'-ddC [23-ddC-Q]	3'
3'-dA (chain terminator) [3-dA-Q]	3'
3'-dC (chain terminator) [3-dC-Q]	3'
3'-dG (chain terminator) [3-dG-Q]	3'
3'-dT (chain terminator) [3-dT-Q]	3'
5-Pyrine Cap [5-PyrCAP]	5'	Image not available.
Acrydite [5Acrd]	5'
Cholesteryl-TEG [Chols-Q]	3'
Cholesteryl-TEG [Chol-TEG]	5', Internal
DNP-TEG [DNP]	5', Internal
Digoxigenin (ester) [Dig]	5', 3', Internal
Phosphorothioation [*]	Internal
Puromycin [Pmycn-Q]	3'