此頁面上的某些內容不提供英文版本，將默認以當前可用的語言顯示。

NHS Ester Labeling of Biomolecules Containing Primary Amino Groups

NHS (N-HydroxySuccinimide) esters and other activated esters (sulfo-NHS, sulfotetrafluorophenyl — STP) are reactive compounds suitable for the modification of amino groups. NHS is the most common type of activated esters.

Usual modifications are fluorescent labels, fluorescence quenchers, and other reporter groups. Alkyne and azido groups can be attached using activated esters to adapt biomolecules to click chemistry.

Especially common are modifications of proteins and peptides since they nearly always contain amino groups. Other examples are modifications of amino-oligonucleotides, amino-modified DNA, and amino-containing sugars.

The reaction of NHS esters with amino groups is strongly pH-dependent: at low pH, the amino group is protonated, and the modification does not occur. At higher-than-optimal pH, hydrolysis of NHS ester is quick, and the yield of modified molecule decreases. The optimal pH value for modification is 8.3-8.5.

Water is the most common solvent used to dissolve NHS esters for biomolecule labeling. If NHS ester is poorly soluble in aqueous solutions, it can be at first dissolved in dimethyl sulfoxide (DMSO) or dimethylformamide (DMF) and then added to a solution of protein in a buffer with pH 8.3-8.5. Note that DMF can degrade into dimethylamine, which has a fishy smell and is able to react with activated esters. Therefore, to label biomolecules, it is important to use high-quality DMF that contains no dimethylamine and has no fishy odor.

We recommend using the following general protocol for the labeling of biomolecules with NHS esters produced by Lumiprobe:

Calculate the required amount of NHS ester using the formula below or our protein labeling calculator:
NHS_ester_weight [mg] = 8 × amino_compound_weight [mg] × NHS_ester_molar_weight [Da] / amino_compound_molar_weight [Da].
8 is a molar excess of NHS ester. It is an empirical value for mono-labeling, suitable for many common proteins and peptides. However, in some cases using less or more NHS ester can increase the yield of the modified biomolecule. It depends on protein structure, reagent used for labeling, and its solubility. The molar weight of Lumiprobe products can be found on the corresponding product pages.
For example, to label 3 mg of BSA (molar weight 66500 Dalton) with Cy5 NHS ester (molar weight 616 Dalton), and obtain maximum yield of mono-labeled product, one should use 8 × 3 mg × 616 Da / 66500 Da = 0.22 mg of Cy5 dye NHS ester.
Calculate the volume of the reaction mixture. The optimal biomolecule concentration in labeling reaction is 1-10 mg per mL. The labeling can be performed on any scale, from nanomols to dozens of grams. If you label a low amount of biomolecule, keep the volume of the reaction mixture at a minimum (10-20 uL).
Dissolve NHS ester in 1/10 reaction volume of water, DMF, or DMSO. Dimethylamine-free DMF or water are preferred solvents. NHS ester dissolved in DMF can be stored in solution for 1-2 months at −20ºC. The aqueous solution of NHS ester should be used immediately after preparation.
Dissolve biomolecule in 9/10 reaction volume of buffer with pH 8.3-8.5.
0.1 M Sodium bicarbonate solution has appropriate pH. Another alternative is 0.1 M phosphate buffer. Note that pH is the most important factor for successfully labeling biomolecule with NHS ester. Avoid buffers containing amines (Tris-based buffers can sometimes be used but are not recommended. Tris contains amino group, but its affinity to activated esters is low).
When doing large-scale labeling (using hundreds of milligrams of NHS ester), note that the mixture tends to acidify with time because of the hydrolysis of NHS ester. Monitor pH, or use a more concentrated buffer then.
Add NHS ester solution to the solution of biomolecule, and vortex well. Keep on ice overnight, or at room temperature from 1 to 4 hours.
Purify the conjugate using the appropriate method: gel-filtration for macromolecules is the most common. Chromatography is another alternative. For proteins and nucleic acids, ethanol or acetone precipitation can be used. Organic impurities (such as N-hydroxysuccinimide, NHS ester, and acid produced by hydrolysis) are almost always easily separated by these methods.

相關的產品

3-馬來醯亞胺丙酸NHS-酯 (3-Maleimidopropionic acid NHS-ester)

具有胺反應性琥珀醯亞胺酯和巰基反應性的馬來醯亞胺基團的雙功能交聯劑。

顯示價格

貨號	數量	價格	交貨時間	購買此產品
3419-100mg	100 mg	–	現貨
3419-500mg	500 mg	$110	現貨

樣品請求

Found better price? Let us know and we will propose the way forward!

AF 488 TFP 酯 (AF 488 TFP ester)

綠色螢光染料 AF 488 的四氟苯酯，用於標記蛋白質、多肽和修飾寡核苷酸中的氨基。

顯示價格

貨號	數量	價格	交貨時間
118T0	1 mg	$165	現貨
218T0	5 mg	$510	現貨
418T0	25 mg	$1650	現貨

貨號	數量	價格	交貨時間
1C920	1 mg	$110	現貨
2C920	5 mg	$640	現貨
4C920	25 mg	$1640	現貨
5C920	50 mg	$2090	現貨
6C920	100 mg	$2840	現貨

貨號	數量	價格	交貨時間
14420	1 mg	$125	現貨
24420	5 mg	$260	現貨
44420	25 mg	$510	現貨
54420	50 mg	$895	現貨
64420	100 mg	$1490	現貨

貨號	數量	價格	交貨時間
34720	10 mg	$80	現貨
44720	25 mg	$110	現貨
54720	50 mg	$135	現貨
64720	100 mg	$210 $178	現貨
94720	1 g	$1000 $970	現貨
K4720	5 g	$3570 $2990	現貨

貨號	數量	價格	交貨時間
2584-5mg	5 mg	–	現貨
2584-10mg	10 mg	$90	現貨
2584-25mg	25 mg	$180	現貨
2584-100mg	100 mg	$450	現貨
2584-500mg	500 mg	$1700	5 天
2584-1g	1 g	$3000	現貨
2584-5g	5 g	請查詢	現貨

貨號	數量	價格	交貨時間
4245-100mg	100 mg	$125	現貨
4245-500mg	500 mg	$525	現貨
4245-1g	1 g	$990	現貨

貨號	數量	價格	交貨時間
2782-100mg	100 mg	$110	現貨
2782-500mg	500 mg	$485	現貨
2782-1g	1 g	$895	現貨

貨號	數量	價格	交貨時間
22D20	5 mg	–	現貨
42D20	25 mg	$315	現貨
52D20	50 mg	$580	現貨
62D20	100 mg	$885	現貨

貨號	數量	價格	交貨時間
18120	1 mg	$110	現貨
28120	5 mg	$210	現貨
48120	25 mg	$350	現貨
58120	50 mg	$595	現貨
68120	100 mg	$790	現貨

貨號	數量	價格	交貨時間
3056-10mg	10 mg	$145	現貨
3056-25mg	25 mg	$225	現貨
3056-100mg	100 mg	$550	現貨

貨號	數量	價格	交貨時間
1V220	1 mg	$125	5 天
2V220	5 mg	$325	現貨
4V220	25 mg	$510	現貨
5V220	50 mg	$895	現貨
6V220	100 mg	$1490	現貨

貨號	數量	價格	交貨時間
41720	25 mg	$95	現貨
51720	50 mg	$180	現貨
61720	100 mg	$290	現貨
91720	1 g	請查詢	現貨

貨號	數量	價格	交貨時間
30720	10 mg	$110	現貨
40720	25 mg	$210	現貨
50720	50 mg	$410	現貨
60720	100 mg	$595	10 天

貨號	數量	價格	交貨時間
53720	50 mg	$110	現貨
63720	100 mg	$210	現貨
73720	1 g	$950	現貨
83720	5 g	請查詢	現貨

貨號	數量	價格	交貨時間
13320	1 mg	$91	現貨
23320	5 mg	$119	現貨
43320	25 mg	$345	現貨
53320	50 mg	$557	現貨
63320	100 mg	$890	現貨

搜索產品

NHS Ester Labeling of Biomolecules Containing Primary Amino Groups

We recommend using the following general protocol for the labeling of biomolecules with NHS esters produced by Lumiprobe:

相關的產品

搜索產品

免費

無手續費！

幫助中心

更多資訊

化學分析證書

Lumiprobe Corporation (美洲)