BioActs offers the full spectrum of fluorescent dyes such as FSD FluorTM, Flamma® Fluors, ICG, and Other Dyes,
and also offers Fluorescent Quenchers, Crosslinkers, Fluorescent Antibodies, Bioprobes,
and Microspheres, Magnetic Beads, Dye Labeling Kit, etc.
BioActs offers a broad range of Flamma® Fluors dyes equipped with variety of reactive and functional groups, which can cover the full spectral range from UV to NIR with their excellent fluorescence performance. Characteristic features of these superior dyes are strong absorption, high fluorescence quantum yield and high photostability. Flamma® dyes maintain good fluorescence activity and stability after conjugation to biomolecules and allow the detection of low-abundance biological structures with great sensitivity. The dyes are compatible with optical conditions of most of fluorescent equipment and are ideal for any applications in biological studies.
- Covering the full spectral range from UV to NIR
- Equipped with a variety of reactive groups: NHS and Sulfo-NHS ester, Vinylsulfone, Maleimide, Click chemistry, isothiocyanate, hydrazide
and hydrophobic substances.
- High quantum yields and photostability
- High purity and compatible with most of biomolecules
Flamma® Fluors NHS ester / Sulfo-NHS ester
Succinimidyl (NHS) esters are reliable activating moiety for amine labeling due to the formation of the strong amide bond. NHS esters are generally stable when storing in anhydrous and the dark condition at -20. NHS ester dyes display good reactivity toward aliphatic amines yet low reactivity with aromatic amines, alcohols, phenols and histidine. The basicity of an amine is an important factor for its reactivity: virtually all proteins have lysine residues, and most of them have a free N-terminus amine. The reactivity of ε-amino group at lysine is pH dependent that the optimal pH for labeling lysine residue is 8.5~9.5. However, the primary amine at N-terminus usually has a pKa value of ~7, thus it can be selectively conjugated by running the reaction in neutral pH. Due to the solubility issue, Flamma® Fluors NHS esters are required to be dissolved in an organic solvent such as DMSO or DMF and added to aqueous solution. To overcome this limitation, BioActs offers water soluble Flamma® Fluors Sulfo-NHS ester dyes, which can eliminate the usage of organic solvents in the conjugation reaction. NHS and Sulfo-NHS ester dyes are unstable under humid condition, thus they should be in a lyophilized form or a solution in the anhydrous organic solvent such as DMF or DMSO and stored at -20 ℃.
Flamma® Fluors Vinylsulfone
BioActs’ leading technology developed highly reactive yet stable and pH insensitive Flamma® Fluors Vinylsulfone dyes. Vinylsulfone reactive group mainly react with the primary amine of biomolecules under a wide range of pH from 5 to 10 though the labeling reaction rate is proportional to the basicity of medium. Vinylsulfone dyes are stable in both organic and aqueous solution at higher temperature, thus they can be dissolved in water avoiding organic solvents such as DMSO or DMF, and the aqueous stock solution can be stored in a refrigerator. Vinylsulfone reacting group is added by an amine via 1,2 addition pathway to form a stable amino linkage between dye and the biomolecule, therefore none of side product would be generated during conjugation step. BioActs recommends Flamma® Fluors Vinylsulfone for labeling biomolecules in harsh conditions such as having less reactive amines, running the reaction in prolong period, at high temperature or under strong basic or acidic environment.
Flamma® Fluors Isothiocyanate
BioActs offers a series of Flamma® Fluors isothiocyanates, which are moderately reactive but quite stable in water and most organic solvents. Isothiocyanates form reasonably stable thiourea linkage upon reaction with amines. Whereas labeling of protein with NHS esters can typically be done at pH 8.3, conjugation for isothiocyanates usually require pH above 9. This basic isothiocyanate labeling condition may be a factor for working with basic-environment tolerable biomolecules that DNA and most polysaccharides can be modified in a relatively basic pH.
Flamma® Fluors Carboxylic acid
Flamma® Fluors Carboxylic acids are non-reactive form of Flamma® Fluors that can be used as a reference standard for dye-conjugates. Additionally, this carboxylic acid can be converted to a reactive amine form by using standard chemical techniques or coupled to hydrazines. Flamma® Fluors carboxylic acids can be coupled with amines at small molecules or peptides by standard amide bond coupling conditions.
Flamma® Fluors maleimide
Maleimide is an excellent reactive group that can specially label thiol of cysteine residue without interacting with amino functionality. In labeling process, thiol is added to the double bond of maleimide via 1,4-addition pathway to form thioether linkage. Maleimides apparently do not react with methionine, histidine or tyrosine, but they are reacted with amines in higher pH than reaction of maleimides. BioActs offers Flamma® Fluors maleimide series as thiol-reactive fluorescence dyes.
Flamma® Fluors Hydrazide / Dichlorotrazine
Flamma® Fluors hydrazide dyes can label aldehyde and ketone through reductive amination reaction to form an imine linkage. The main labeling target for hydrazides are free reducing sugars on biomolecules, and prior to conjugation, primary and secondary alcohols on polysaccharide and glycoprotein are usually oxidized to aldehyde and ketone. Fluorescent modification of aldehyde or carbonyl groups in carbohydrates is also frequently utilized for their analysis by HPLC, capillary electrophoresis and other methods. Hydrazide dyes can also label biomolecules, which introduced aldehyde by genetical or chemical modification.
Flamma® Fluors dichlorotriazine is for labeling hydroxyl groups. Hydroxyls irreversibly displace one of chlorine at triazine ring via SNAr reaction pathway to yield an aryl ether linkage. Dichlorotriazines are among the few reactive groups that are reported to react directly with polysaccharides and other alcohols in aqueous solution, provided that the pH is >9 and other nucleophiles are not present.
Flamma® Fluors for Click Chemistry
The most widely utilized click chemistry is 1,3-dipolar cycloaddition between an azide and an alkyne to produce 1,4-disubstituted 1,2,3-triazole. There are two types of 1,3-dipolar cycloaddition methods: copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC). BioActs offers Flamma® Fluors Alkyne dyes for CuAAC, Flamma® Fluors ADIBO products for SPAAC and Flamma® Fluors Azide dyes for both CuAAC and SPAAC.
Flamma® Fluors Amine
Flamma® Fluors Amine dyes have an attached primary amine, which connected through a spacer, and can be used as a reference standard for dye-conjugates. These amine dyes can be conjugated with carboxylic acids at small molecules or peptides by standard amide bond coupling conditions.
Flamma® Fluors Thiol
Flamma® Fluors thiol dyes have an attached primary thiol, which connected through a spacer. These thiol dyes can be labeled to biomolecules through disulfide bond formation with thiol of cysteine residue.
Figure 1. Absorption (upper) and emission (bottom) spectra overlap of Flamma® Fluors
Figure 2. Immunofluorescence imaging and in situ hybridization imaging
Figure 3. Fluorescence images of Flamma® 749 (upper) and Flamma® 774 (bottom) carboxylic acid injected mouse model
|Flamma® Fluors NHS ester||Availability : Fluorescence labeling||Reacting Functionality : Amine reactive dyes|
|Flamma® Fluors Sulfo-NHS ester||Availability : Fluorescence labeling||Reacting Functionality : Amine reactive dyes|
|Flamma® Fluors Vinylsulfone||Availability : Fluorescence labeling||Reacting Functionality : Amine reactive dyes|
|Flamma® Fluors Isothiocyanate||Availability : Fluorescence labeling||Reacting Functionality : Amine reactive dyes|
|Flamma® Fluors Maleimide||Availability : Fluorescence labeling||Reacting Functionality : Thiol reactive dyes|
|Flamma® Fluors Hydrazide||Availability : Fluorescence labeling||Reacting Functionality : Aldehyde, Ketone reactive dyes|
|Flamma® Fluors Dichlorotriazine||Availability : Fluorescence labeling||Reacting Functionality : Hydroxyl reactive dyes|
|Flamma® Fluors Carboxylic acid||Availability : Fluorescence labeling||Reacting Functionality : Functionalized dyes|
|Flamma® Fluors Amine||Availability : Fluorescence labeling||Reacting Functionality : Functionalized dyes|
|Flamma® Fluors Thiol||Availability : Fluorescence labeling||Reacting Functionality : Functionalized dyes|
|Flamma® Fluors Alkyne||Availability : Fluorescence labeling||Reacting Functionality : Click chemistry dyes|
|Flamma® Fluors PEG4-Alkyne||Availability : Fluorescence labeling||Reacting Functionality : Click chemistry dyes|
|Flamma® Fluors ADIBO||Availability : Fluorescence labeling||Reacting Functionality : Cu-free click chemistry dyes|
|Flamma® Fluors Azide||Availability : Fluorescence labeling||Reacting Functionality : Aldehyde, Ketone reactive dyes|