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Cyanine dyes

Cyanine dyes are molecules containing polymethine bridges between two nitrogen atoms with a delocalizedcyanine_dyes charge which have been used for many years as dyes in life science. Since the Cy3, Cy5 and Cy7 were made commercially available as succinimidyl esters in the early 1990s, cyanine dyes began to be used widely as labels for nucleic acids. Because of the good properties of low non-specific binding to biomolecules and bright fluorescence owing to their huge extinction coefficients and good quantum yields, the Cy dyes have been widespread used in DNA and RNA labelling. Cyanine dyes can be divided into two groups based on water solubility: non-sulfonated cyanines and sulfonated cyanines.

Non-sulfonated cyanines
Available non-sulfonated dyes include Cy3, Cy3.5, Cy5, Cy5.5, Cy7, and Cy7.5. Cy stands for 'cyanine', and the first digit identifies the number of carbon atoms between the indolenine groups. The suffix .5 is added for benzo-fused cyanines. Most derivatives of non-sulfonated cyanines have low aqueous solubility except for hydrochlorides of hydrazides and amines. They are organic co-solvent soluble (5-20% of DMF or DMSO). When these molecules are used for biomolecule labeling, they should be dissolved in organic solvent first, and added to a solution of biomolecule (protein, peptide, amino-labeled DNA) in appropriate aqueous buffer. Fluorescent properties of non-sulfonated cyanines have little dependence on solvent and surrounding.

Sulfonated cyanines
Available sulfonated cyanines include sulfo-Cy3, sulfo-Cy5, and sulfo-Cy7, which have additional sulfo-groups that facilitate dissolution of dye molecules in aqueous phase. Charged sulfonate groups decrease aggregation of dye molecules and heavily labeled conjugates. Sulfonated cyanines are highly water soluble, and they do not use organic co-solvent for the labeling in aqueous environment.

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  1. Cy7 maleimide (non-sulfonated)
    A8141 Cy7 maleimide (non-sulfonated)
    Summary: Labeling of cysteine residues, as well as other thiolated molecules
      soluble in organic solvents (dmso
      low solubility in water
  2. Cy5.5 maleimide (non-sulfonated)
    A8140 Cy5.5 maleimide (non-sulfonated)
    Summary: Labeling of cysteine residues, as well as other thiolated molecules
      ≥74.1 mg/mL
      insoluble in etoh
      insoluble in h2o
  3. Cy5 maleimide (non-sulfonated)
    A8139 Cy5 maleimide (non-sulfonated)
     1 Citation
    Summary: Labeling of cysteine residues, as well as other thiolated molecules
      ≥64.1 mg/mL
      ≥65 mg/mL
      insoluble in h2o
  4. Cy3 maleimide (non-sulfonated)
    A8138 Cy3 maleimide (non-sulfonated)
    Summary: Labeling of cysteine residues, as well as other thiolated molecules
      dmso
      insoluble in water
  5. Cy5 carboxylic acid
    A8137 Cy5 carboxylic acid
    Summary: Non-reactive fluorophore, for control experiments, and for calibration
  6. Cy7.5 carboxylic acid (non-sulfonated)
    A8136 Cy7.5 carboxylic acid (non-sulfonated)
    Summary: Non-reactive fluorophore, for control experiments, and for calibration
      soluble in organic solvents (dmso
      low solubility in water
  7. Cy7 carboxylic acid (non-sulfonated)
    A8135 Cy7 carboxylic acid (non-sulfonated)
    Summary: Non-reactive fluorophore, for control experiments, and for calibration
      soluble in organic solvents (dmso
      low solubility in water
  8. Cy5.5 carboxylic acid (non-sulfonated)
    A8134 Cy5.5 carboxylic acid (non-sulfonated)
    Summary: Non-reactive fluorophore, for control experiments, and for calibration
      ≥213 mg/mL
      ≥16.73 mg/mL
      insoluble in h2o
  9. Cy5 Bis carboxylic acid
    A8775 Cy5 Bis carboxylic acid
    Summary: Non-reactive fluorophore, for control experiments or calibration,water soluble
      soluble in dmso
  10. Cy3 Bis carboxylic acid
    A8774 Cy3 Bis carboxylic acid
    Summary: Non-reactive fluorophore, for control experiments or calibration,water soluble
      soluble in dmso

Items 31-40 of 48

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