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CAL Fluor Red 635 dT Amidite

CAL Fluor Red 635 dT Amidite

CAL Fluor Red 635 dT Amidite, 100 μmol, ABI (5 mL / 20 mm Septum)

A phosphoramidite used for CAL Fluor Red 635-dT labelling of oligonucleotides.

Key features

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  • Used to add a orange-red fluorescent dye internally or to the 5' end of an oligonucleotide.
  • Maximal emission around 635 nm. Alternative to LC Red 640.
  • Quenched by BHQ-2.
  • Has DMT functionality.
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Item ID BNS-5084T-100
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Product information

Historically, there was a limited selection of dyes available for multiplex PCR: TET, JOE, VIC™, HEX, Texas Red®, Cy™ 3, and Cy™ 5. In recent years, the selection and quality of reporters and quenchers has dramatically improved. LGC, Biosearch Technologies has developed the CAL Fluor Dyes, a set of fluorescent dyes specifically designed for qPCR instruments. These novel xanthene fluorophores not only replicate the applicability of previous dyes, they have further unique patented features. These dyes can be efficiently manufactured and remain stable through oligo synthesis and work up. The attachment chemistry linking the CAL Fluor Dyes to biomolecules eliminates the problem of multiple isomers. This results in dye labels that are easier to manufacture, have a single RP-HPLC peak and have well-defined emission spectra. CAL Fluor Dyes are available as CPGs and as phosphoramidites for oligonucleotide synthesis, which results in more efficient label incorporation and fewer purification steps than post-synthesis labeling. The CAL Fluor Dyes have emission maxima from 544 nm to 637 nm and can be paired with BHQ-1 or BHQ-2 for efficient quenching in a variety of probe formats. Multiplex suggestions and PCR instrument compatibility of CAL Fluor Dyes can be found here. Carboxylic acids of the CAL Fluor Dyes 560, 590, and 610 are available to use for peptide labelling.


  • Formula: C88H105Cl2N9O13P
  • Molecular Weight: 1598.71
  • Appearance: blue green solid
  • Absorption Maximum (Lambda Max): 618
  • Extinction Coefficient at Lambda max: 112000
  • Extinction Coefficient at 260 nm: 44900
  • Fluorescence Maximum: 637

Product usage:

  • Deprotection conditions: For a 1 mol to a 200 nmol synthesis scale, cleave and deprotect the CAL dye labeled oligo in 200 L of 2-(2aminoethoxy)-ethanol (Aldrich # A54059) at 60 °C for 4.0 hours. The dye labeled CPG will lose the blue color after the addition of the 2-(2aminoethoxy)-ethanol. Remove the sample from the heat block and cool to approximately 25 °C. Add 1.0 mL of 1,4-dioxane. Shake the tube by hand. Centrifuge at 13,000 RPM for 30 seconds and remove the supernatant with a pipette. Repeat the process two times with another 1.0 mL of 1.4-dioxane until the blue color appears. As the treatment with the 1,4-dioxane removes the base the sample should regain its blue color. After the removal of the 1,4-dioxane, add 200µL of water to elute the oligo. Before analysis filter off CPG support. CAL Fluor Red 635 will degrade if left in the presence of base for an extended amount of time.The use of strong bases, such as concentrated ammonia, causes degradation of the dye and should be avoided. The use of methylamine should also be avoided.
  • CAL Fluor Red 635 is light sensitive. Prolonged exposure to light may cause photo bleaching.This product is susceptible to oxidation when left out in the open or undessicated.Unused amidite solution can be stored under argon and its functionality maintained for up to 24 hours.Image of cleaved and deprotected structure:
  • The mass this product adds after conjugation and work-up (the additional mass seen by mass spectrometry) is: 1158

Storage and handling:

  • Storage conditions: -20 °C

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