Activated esters
Primary or secondary amino groups are ubiquitous in biomolecules. They are present in proteins and peptides as ε-amino groups of lysines and N-terminal amino groups. Many natural and synthetic small molecules are amines, and DNAs with amino groups can be prepared by solid phase synthesis, and enzymatically.
Amino groups can be modified by acylation with various activated carbonyl compounds. Among these compounds, activated N-hydroxysuccinimide esters are most suitable for biolabeling and bioconjugation applications.
Compared to other activated esters, NHS derivatives possess good stability in aqueous environment. Optimal pH for the coupling of amines with NHS esters in aqueous buffers is 8.3-8.5. Labeling is also possible in organic solvents. Polar aprotic solents, such as DMF or DMSO, are preferred. One equivalent of tertiary amine base, such as triethylamine, or diisopropylethylamine (DIPEA) is necessary to achieve efficient amine acylation in non-aqueous solution.
(5,6)-FAM diacetate NHS ester
Amine-reactive fluorescein (FAM) derivative, a mixture of 5- and 6-isomers. The reagent becomes brightly green fluorescent once it is hydrolyzed while diffusing into cells. A fluorescent tracer.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 2934-1mg | 1 mg | – | in stock | |
| 2934-25mg | 25 mg | $160 | in stock | |
| 2934-50mg | 50 mg | $270 | in stock | |
| 2934-100mg | 100 mg |
$520
|
in stock |
AF 343 (Coumarin)-X-NHS ester
AF 343 (Coumarin) is a blue emitting dye that can serve as a FRET donor for fluorescein (FAM). This structure features a linker between Coumarin 343 fluorophore, and the functional group. It provides better solubility, and spatial separation between the dye, and the functional group.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 12620 | 1 mg | $110 | in stock | |
| 22620 | 5 mg | $210 | in stock | |
| 42620 | 25 mg |
$410
|
in stock | |
| 52620 | 50 mg |
$695
|
in stock | |
| 62620 | 100 mg |
$1190
|
in stock |
AF 430 NHS ester
AF 430 is a hydrophilic coumarin dye with emission in the green-yellow range. The NHS ester is used for the labeling of amine groups.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 10820 | 1 mg | $110 | in stock | |
| 20820 | 5 mg | $165 | in stock | |
| 40820 | 25 mg | $380 | in stock | |
| 50820 | 50 mg |
$695
|
in stock | |
| 60820 | 100 mg |
$1190
|
in stock |
AF 488 NHS ester
AF 488 NHS ester, a bright, photostable, and hydrophilic fluorescent dye for the green channel.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 11820 | 1 mg | $125 | in stock | |
| 21820 | 5 mg | $325 | in stock | |
| 31820 | 10 mg |
$480
|
in stock | |
| 41820 | 25 mg |
$950
|
in stock | |
| 51820 | 50 mg |
$1625
|
in stock | |
| 61820 | 100 mg |
$2090
|
in stock |
AF 488 TFP ester
Tetrafluorophenyl ester of green fluorescent dye AF 488 for labeling amino groups in proteins, peptides, and modified oligonucleotides.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 118T0 | 1 mg | $165 | in stock | |
| 218T0 | 5 mg |
$510
|
in stock | |
| 418T0 | 25 mg |
$1650
|
in stock |
AF 532 NHS ester
NHS-ester of AF 532 dye for protein, peptide, and modified oligonucleotide labeling via reaction with amino groups.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 1C820 | 1 mg | $140 | in stock | |
| 2C820 | 5 mg |
$450
|
in stock | |
| 4C820 | 25 mg |
$1460
|
in stock | |
| 5C820 | 50 mg |
$1890
|
in stock | |
| 6C820 | 100 mg |
$2640
|
in stock |
AF 555 NHS ester
AF 555 NHS ester, a bright, photostable, and hydrophilic fluorescent dye for the yellow channel.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 1K820 | 1 mg | $140 | in stock | |
| 2K820 | 5 mg |
$450
|
in stock | |
| 4K820 | 25 mg |
$1460
|
in stock | |
| 5K820 | 50 mg |
$1890
|
in stock | |
| 6K820 | 100 mg |
$2640
|
in stock |
AF 568 NHS ester
AF 568 derivative for labeling proteins and other high- and low-molecular weight ligands with free amines.| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 14820 | 1 mg | $125 | in stock | |
| 24820 | 5 mg | $325 | in stock | |
| 44820 | 25 mg |
$720
|
in stock | |
| 54820 | 50 mg |
$1325
|
in stock | |
| 64820 | 100 mg |
$2090
|
in stock |
AF 594 NHS ester
Red-fluorescent NHS-ester of AF 594 dye for labeling proteins, peptides, antibodies, and any molecules containing an -NH2 group. Pure 5-isomer| Cat. # | Quantity | Price | Lead time | Buy this product |
|---|---|---|---|---|
| 2825-1mg | 1 mg | $125 | in stock | |
| 2825-5mg | 5 mg |
$425
|
in stock | |
| 2825-25mg | 25 mg |
$1240
|
in stock | |
| 2825-50mg | 50 mg |
$1890
|
in stock | |
| 2825-100mg | 100 mg |
$2640
|
in stock |