Enhanced Diagnostic Tools
These dyes are available as NHS Esters and are conjugated post synthesis to an amino-modified
oligo and two step HPLC purifications are required. The spectral diversity of the
Alexa Fluor dyes make them ideal tools for multicolor applications such as fluorescence
in situ hybridization (FISH) and microarray experiments. Our wide selection of dyes
spans the visible spectrum and beyond, providing enormous flexibility in choosing
a label that is compatible with microarray scanners and fluorescence microscopes.
The Alexa Fluor dyes have several properties that make them superior to other fluorescent
Oligonucleotides labeled with Alexa Fluor have many advantages:
• High water solubility.The Alexa Fluor dyes are highly
water soluble, making them ideal for hybridization experiments. Nucleic acids labeled
with the Alexa Fluor dyes do not aggregate or precipitate, even in high-salt conditions.
• pH independence. Fluorescence of the Alexa Fluor conjugates
is not pH sensitive in the ranges used for hybridization solutions and microscopy
• Resistance to photobleaching. The enhanced photostability
of Alexa Fluor dyes makes them ideal for applications requiring imaging, such as
FISH and microarrays.
• High signal correlation.
The Alexa Fluor 555/Alexa Fluor 647 dye pair provides better signal correlation
and therefore higher resolution of diff erentially expressed genes than the commonly
used Cy3/Cy5 dye pair
Similar alternatives include the
DyLight Fluors and the Atto.
Contact your Account Representative for pricing on Alexa dye labeled oligonucleotides.
For additional information, please Contact us.
Price/labeling, purification and synthesis is an additional charge
Desalt or cartridge (RP1) purification is acceptable for most common phosphoramidite
modifiers. However, additional purification is strongly recommended for modifiers
that require NHS-ester chemistry to conjugate a dye through an amine linker such
as Molecular Probes dyes.
Due to the chemistry of many modifications, yield will be approximately 40 - 60
% less than a standard oligo.
Please see our yield chart for details.
Every oligo synthesized is strictly controlled for quality by using either MALDI-TOF
mass spectrometry or polyacrylamide gel electrophoresis (PAGE) analysis. Final yields
are determined using UV absorbance at OD260. In addition, we perform
QC methods tailored to specific modifications, such as OD ratio measurement where