All Photos(4)





BioPerformance Certified, ≥99.5% (titration), suitable for cell culture

Sign Into View Organizational & Contract Pricing

4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid, N-(2-Hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid)
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
EC Number:
MDL number:
PubChem Substance ID:


BioPerformance Certified

Quality Level


≥99.5% (titration)


crystalline powder

storage condition

dry at room temperature


cell culture | mammalian: suitable
competitive inhibition ELISA: suitable


endotoxin and total aerobic microbial count, tested



useful pH range


pKa (25 °C)


cation traces

Fe: ≤5 ppm


≤0.05 at 260 in H2O at 0.1 M
≤0.05 at 280 in H2O at 0.1 M


suitable for Western blot
suitable for component for culture media


clinical research
diagnostic assay manufacturing
general analytical
life science and biopharma

foreign activity

DNase, RNase, NICKase, protease, none detected

SMILES string




InChI key


Looking for similar products? Visit Product Comparison Guide

General description

HEPES buffer does not confer cytotoxic effects on cells and thus can be used in animal cell cultures.
HEPES has been described as one of the best all-purpose buffers available for biological research. At biological pH, the molecule is zwitterionic, and is effective as a buffer at pH 6.8 to 8.2. HEPES has been used in a wide variety of applications, including tissue culture. It is commonly used to buffer cell culture media in air. HEPES finds its usage in in vitro experiments on Mg.
HEPES, or 4-(2-hydroxyethyl)piperazine-1-ethane-sulfonic acid, is a zwitterionic N-substituted aminosulfonic acid buffer. It demonstrates outstanding buffering capacity in the pH range of 6.8 to 8.2, boasting a pKa of 7.48 at 25°C. Widely acknowledged as one of the most versatile buffers, HEPES is extensively utilized in cell biology, biochemical, and biological research. A notable attribute is its non-reactivity with metal ions. Unlike many buffers, HEPES does not form significant complexes with most metals, making it suitable for applications involving metal ions without affecting their activity. This characteristic enhances its utility as a "non-coordinating buffer." In cell culture, HEPES excels in maintaining a stable physiological pH, even amidst fluctuations in carbon dioxide concentration resulting from cellular respiration. This sets it apart from bicarbonate buffers (NaHCO3), which, though commonly used, are less effective in pH stability.

HEPES also proves advantageous in various biological and biochemical processes. Its ampholytic nature makes it suitable as a separator for creating pH gradients in isoelectric focusing, a technique often employed in protein separation and analysis. Moreover, HEPES exhibits minimal interference with DNA-restriction enzyme reactions compared to buffers with fewer substituted amine groups, such as Tris. This makes it a preferred choice for applications involving DNA manipulation and analysis. Beyond these specific applications, HEPES is valuable in numerous other biological and biochemical processes, including immunoprecipitation, cell lysis, and live cell imaging. Its versatility, coupled with exceptional pH buffering capacity and minimal interaction with other molecules, establishes HEPES as an indispensable tool across diverse research domains.


HEPES has been used:
  • To supplement Dulbecco′s modified Eagle′s medium to culture and maintain cell lines
  • As a component of platelet suspension buffer
  • To supplement Hank′s basic salt solution, which is used to wash pancreatic tissue
  • As a component of wash buffer and blocking buffer in the purification and quantification of protein with enzyme-linked immunosorbent (ELISA) assay
  • For the adjustment and maintenance of pH of biological solutions
  • As a component of Hank′s balanced salt solution (HBSS) and dissociation medium to study neuronal development
  • For homogenization of tissue and in the preparation of cytosolic and nuclear extract from cells
  • As a component of keratinocyte and fibroblast culture medium

Features and Benefits

  • Tested to confirm low levels of heavy metal contamination, ensuring suitability for various applications
  • Highly soluble in water with a useful pH range of 6.8 - 8.2 and pKa of 7.5 at 25 °C
  • Negligible metal ion binding
  • Less toxic to cells than other buffers such as Tris and phosphate
  • Stable in a wide pH range
  • Tested for Endotoxins and Total Aerobic Microbial Count
  • Free from DNase, NICKase, RNase, Endonuclease, Exonuclease and Protease

Other Notes

For additional information on our range of Biochemicals, please complete this form.

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Documents related to the products that you have purchased in the past have been gathered in the Document Library for your convenience.

Visit the Document Library

Difficulty Finding Your Product Or Lot/Batch Number?

Product numbers are combined with Pack Sizes/Quantity when displayed on the website (example: T1503-25G). Please make sure you enter ONLY the product number in the Product Number field (example: T1503).


Product Number
Pack Size/Quantity

Additional examples:





enter as 1.000309185)

Having trouble? Feel free to contact Technical Service for assistance.

Lot and Batch Numbers can be found on a product's label following the words 'Lot' or 'Batch'.

Aldrich Products

  • For a lot number such as TO09019TO, enter it as 09019TO (without the first two letters 'TO').

  • For a lot number with a filling-code such as 05427ES-021, enter it as 05427ES (without the filling-code '-021').

  • For a lot number with a filling-code such as STBB0728K9, enter it as STBB0728 without the filling-code 'K9'.

Not Finding What You Are Looking For?

In some cases, a COA may not be available online. If your search was unable to find the COA you can request one.

Request COA

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service