馬來酰亞胺活性基團的熒光染料是目前和帶有巰基的生物分子比如說多肽、蛋白或者小分子做標記或者偶聯的的試劑。

Maleimides是一個對thiols有選擇性的親電化合物，在自然界中基本上不存在Maleimides基團，而有的thiols存在，馬來酰亞胺和巰基會作為半胱氨酸殘基在多肽和蛋白中相遇，雖然的DNA中不含有巰基，但是人工的寡核苷酸是容易制備出來的。

Cy3 maleimides , Cy5 maleimides , Cy7 maleimides標記帶有SH的多肽、蛋白還有生物小分子的具體實驗方法和實驗步驟。

1. Dissolve the protein or other molecule containing thiol to be labeled in degassed buffer (PBS, Tris, HEPES are good, although others buffers containing no thiols can be used) at pH 7-7.5 in plastic vial. Buffer can be degassed by applying vacuum on it for several minutes, or by bubbling through inert gas (nitrogen, argon, or helium). For proteins, good concentration is between 1-10 mg/mL.

2. Add an excess of TCEP (tris-carboxyethylphosphine) reagent to reduce disulfide bonds, flush with inert gas, and close. 100x molar excess of TCEP is fine. Keep the mixture for 20 minutes at room temperature.

3. Dissolve maleimide in DMSO or fresh DMF (1-10 mg in 100 uL).

4. Add dye solution to thiol solution (20x fold excess of dye), flush vial with inert gas, and close tightly. 5. Mix thoroughly, and keep overnight at room temperature, or 4 Celsius. 6. Purify by gel filteration, HPLC, FPLC, or electrophoresis

For maleimides with poor aqueous solubility, like most dye maleimides, we recommend use of cosolvent (DMF or DMSO). Maleimides with good aqueous solubility (like sulfo-Cy maleimides) can be dissolved in water. If precipitation occurs, increase content of organic co-solvent in the mixture to achieve better labeling.

相關試劑信息：

Cyanine3 alkyne

Cy3 alkyne

Cyanine3 azide

Cy3 azide

Cy3 N3

Cyanine3 carboxylic acid  1144107-76-5

Cy3 carboxylic acid

Cyanine3 hydrazide

Cyanine3 maleimide

Cy3 maleimide

Cyanine3 NHS ester   1032678-38-8

Cy3 NHS ester

Cyanine3.5 azide

Cyanine3.5 carboxylic acid  1144107-79-8

Cyanine3.5 NHS ester

Cy3.5 NHS ester

Cyanine5 alkyne

Cyanine5 amine

Cy5 amine

Cy5 NH2

Cyanine5 azide

Cy5 N3

Cyanine5 Boc-hydrazide

Cyanine5 carboxylic acid

Cyanine5 hydrazide

Cyanine5 maleimide

Cy5 maleimide

Cyanine5 NHS ester  1032678-42-4

Cy5 NHS ester

Cyanine5.5 alkyne

Cyanine5.5 azide

Cyanine5.5 carboxylic acid  1144107-80-1

Cyanine5.5 maleimide

Cyanine5.5 NHS ester

Cyanine7 amine   1650635-41-8

Cy7 amine

Cy7 NH2

Cyanine7 azide

Cy7 azide

Cyanine7 carboxylic acid

Cyanine7 maleimide

Cy7 maleimide

Cyanine7 NHS ester

Cy7 NHS ester

Cyanine7.5 amine

Cyanine7.5 azide

Cyanine7.5 carboxylic acid   1686147-68-1

Cyanine7.5 maleimide

Cyanine7.5 NHS ester

Sulfo-Cyanine 5 NHS ester

Sulfo-Cy 5 NHS ester

Sulfo-Cyanine3 azide

Sulfo-Cy3 azide

Sulfo-Cyanine3 carboxylic acid

Sulfo-Cyanine3 maleimide

Sulfo-Cy3 maleimide

Sulfo-Cyanine3 NHS ester

Sulfo-Cy3 NHS ester

Sulfo-Cyanine5 alkyne

Sulfo-Cyanine5 azide

Sulfo-Cy5 azide

Sulfo-Cyanine5 carboxylic acid   1121756-16-8

Sulfo-Cyanine5 maleimide

Sulfo-Cy5 maleimide

Sulfo-Cyanine7 azide

Sulfo-Cyanine7 carboxylic acid

Sulfo-Cyanine7 NHS ester

Sulfo-Cy7 NHS ester

ncrease content of organic co-solvent in the mixture to achieve better labeling.

以上資料源于西安瑞禧生物科技有限公司

西安瑞禧生物科技有限公司

Xi'an ruixi Biological Technology Co;Ltd