HEPES (4- (2-hydroxyethyl) -1-piperazine ethanesulfonic acid) is a commonly used buffering agent, widely used in biochemical and cell biology experiments due to its strong buffering ability in the pH range. The synthesis process of HEPES buffer is relatively complex, involving multiple steps and chemical reactions. As a manufacturer, Desheng provides an explanation here to help you better understand and use this buffer.

 

HEPES buffer

 

Specific preparation and synthesis steps of HEPES

 

Step 1: Prepare hydroxyethyl piperazine

 

(1) Dissolve piperazine hexahydrate in ethanol to form a transparent and colorless solution.

 

(2) Add ethylene oxide while refluxing under insulation conditions of 80 degrees Celsius.

 

(3) After the reaction is completed, the ethanol is removed by vacuum distillation, and the residue is purified by vacuum separation.

 

(4) Collect the distillate hydroxyethyl piperazine at a boiling range of 125-127 degrees Celsius.

 

In this step, piperazine reacts with ethylene oxide to produce hydroxyethyl piperazine. The process of reflux and vacuum distillation ensures sufficient reaction and purity of the product.

 

Step 2: Prepare sodium chloroethanesulfonate

 

1. Add anhydrous sodium sulfite and distilled water to the flask and heat it externally in a water bath.

 

2. When the reaction solution reaches 90 degrees Celsius, add 1,2-dichloroethane dropwise while maintaining this temperature.

 

3. Continue to reflux after dripping.

 

4. The reaction solution is concentrated under reduced pressure in a 70 degree water bath until the white solid is fully precipitated.

 

5. Suspend the solid in 95% alcohol, heat and reflux, and filter out insoluble substances while still hot.

 

6. Place the clear liquid at 0 ° C, filter with a Buchner funnel the next day, and collect white sheet-like crystals of sodium chloroethanesulfonate.

 

In this step, sodium sulfite reacts with 1,2-dichloroethane to produce sodium chloroethanesulfonate. Pure sodium chloroethanesulfonate crystals can be obtained through vacuum concentration and alcohol reflux.

 

Step 3: Prepare HEPES powder

 

1. Add hydroxyethyl piperazine, sodium chloroethanesulfonate, and water to the flask, and stir the reaction in an oil bath at 110 ° C.

 

2. Add sodium hydroxide dropwise to maintain pH between 9-10 and reflux until the reaction is complete.

 

3. After cooling, use an ion exchange resin H+chromatography column to remove salt and purify.

 

4. Reduced pressure concentration of chromatography solution, decolorization and filtration with activated carbon, concentration of clear liquid, pouring into boiling alcohol, adjusting pH with glacial acetic acid, and cooling with alcohol precipitation to obtain crude HEPES product.

 

5. Pure HEPES products are obtained through recrystallization, cleaning, and drying.

 

In this step, hydroxyethyl piperazine reacts with sodium chloroethanesulfonate to generate HEPES. During the reaction, the pH value is adjusted by adding sodium hydroxide dropwise to ensure the smooth progress of the reaction. Subsequently, pure HEPES products were obtained through processes such as ion exchange, activated carbon decolorization, and recrystallization.

 

Application of prepared HEPES powder properties

 

HEPES has good buffering ability in the pH range of 6.8-8.2, stable chemical properties, is not easily degraded by cells or components in cell culture medium, and has no inhibitory effect on cell growth and biological reactions.

 

Product packaging

 

Due to these excellent characteristics, HEPES is widely used in experiments in biochemistry, molecular biology, and cell biology. For example, in cell culture, HEPES is commonly used to maintain the pH stability of the culture medium; In enzymatic reactions, HEPES can be used as a buffer to ensure that the reaction proceeds under optimal pH conditions.

 

As a professional manufacturer of biological buffering agents, Desheng Company provides high-quality HEPES products to researchers with its advanced technology and strict quality control. We always believe that through continuous technological innovation and service optimization, customers can rest assured and use it with peace of mind. There is a low price promotion for spot goods in the warehouse, with great discounts. If you are interested, please click on the website to inquire about details and purchase!