FAM-xtra™ Phosphoramidite

There are several ways of labeling an oligonucleotide with fluorescein. 6-FAM phosphoramidite might be the most popular fluorescent building block that is widely used to efficiently label an oligonucleotide at the 5’-end with the fluorescein fluorophore. Standard cleavage and deprotection with ammonium hydroxide are used to liberate the fluorescein-labeled oligos. Although 6-FAM has be ubiquitously used for developing a variety of qPCR probes, its fluorescence suffers two serve limitations: a). highly pH dependent; and b). photo-bleach rapidly. FAM-xtra™ Phosphoramidite has been developed to address these two limitations while the well-beloved operational convenience of 6-FAM phosphoramidite is intactly maintained. FAM-xtra Phosphoramidite can be used exactly as is used for 6-FAM phosphoramidite under the same operation conditions without any changes needed. The oligos made from FAM-xtra Phosphoramidite have quite a few great benefits: a). FAM-xtra-labeled oligos have the identical spectra to those of 6-FAM labeled ones; b). FAM-xtra-labeled oligos are much brighter than the corresponding FAM-labeled ones; c). FAM-xtra-labeled oligos have much higher photostability than the corresponding FAM-labeled ones; and d). The fluorescence of FAM-xtra-labeled oligos is much less pH sensitive than that of the corresponding FAM-labeled ones. Under the physiological conditions, the fluorescence of FAM-xtra-labeled oligos is essentially pH-independent, making the FAM-xtra-labeled oligos much more robust qPCR probes.

Protocol

COA

Catalog	Size	Price
6037	50 umoles	Price
6038	100 umoles	Price
6039	10x100 umoles	Price

References

View all 8 references: Citation Explorer

Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide.

Authors:

Ibaraki, Hisako and Kanazawa, Takanori and Takashima, Yuuki and Okada, Hiroaki and Seta, Yasuo

Journal:

Molecules (Basel, Switzerland) (2016)

Non-nucleoside phosphoramidites of xanthene dyes (FAM, JOE, and TAMRA) for oligonucleotide labeling.

Authors:

Kvach, Maksim V and Tsybulsky, Dmitry A and Shmanai, Vadim V and Prokhorenko, Igor A and Stepanova, Irina A and Korshun, Vladimir A

Journal:

Current protocols in nucleic acid chemistry (2013): Unit 4.55

Practical synthesis of isomerically pure 5- and 6-carboxytetramethylrhodamines, useful dyes for DNA probes.

Authors:

Kvach, Maksim V and Stepanova, Irina A and Prokhorenko, Igor A and Stupak, Aleksander P and Bolibrukh, Dmitry A and Korshun, Vladimir A and Shmanai, Vadim V

Journal:

Bioconjugate chemistry (2009): 1673-82

Synthesis and cellular uptake of fluorescently labeled multivalent hyaluronan disaccharide conjugates of oligonucleotide phosphorothioates.

Authors:

Karskela, Marika and Virta, Pasi and Malinen, Melina and Urtti, Arto and Lönnberg, Harri

Journal:

Bioconjugate chemistry (2008): 2549-58

Synthesis of HyBeacons and dual-labelled probes containing 2'-fluorescent groups for use in genetic analysis.

Authors:

Dobson, Neil and McDowell, David G and French, David J and Brown, Lynda J and Mellor, John M and Brown, Tom

Journal:

Chemical communications (Cambridge, England) (2003): 1234-5

Physical properties

Molecular weight	879.94
Solvent	MeCN

Spectral properties

Correction factor (260 nm)	0.32
Correction factor (280 nm)	0.178
Extinction coefficient (cm ^-1 M ^-1)	83000
Excitation (nm)	493
Emission (nm)	517

Storage, safety and handling

H-phrase	H303, H313, H333
Hazard symbol	XN
Intended use	Research Use Only (RUO)
R-phrase	R20, R21, R22
Storage	Freeze (< -15 °C); Minimize light exposure
UNSPSC	12171501

Documents

Protocol
Safety Data Sheet (Catalog 6037)
Safety Data Sheet (Catalog 6038)
Safety Data Sheet (Catalog 6039)
Certificate of Analysis

Telephone
Fax
Email	sales@aatbio.com
International	See distributors
Bulk request	Inquire
Custom size	Inquire
Technical Support	Contact us
Request quotation	Request
Purchase order	Send to sales@aatbio.com
Shipping	Standard overnight for United States, inquire for international

Page updated on October 22, 2025