People working in biochemical labs have relied on good buffer systems since researchers first realized pH could make or break experiments. BES, known by its long name 2-(Bis(2-Hydroxyethyl)Amino)Ethanesulfonic Acid, came into labs in the 1960s, not just from academic curiosity but out of necessity. The wave of research into biological molecules, cell cultures, and enzymes pushed scientists to hunt for buffers that would keep solutions stable without getting in the way. Norman Good and his team, in their look for zwitterionic buffers that wouldn’t mess with reactions, set the foundation. BES soon started turning up in research papers for keeping biological tests honest, supporting precise results in all kinds of sensitive assays.
BES didn’t take long to prove its value in the lab. Researchers needed substances that would not just set a pH, but keep it steady, especially where simple phosphate or Tris buffers were not enough. BES came up as a strong option, with unique chemical features. It’s now a common buffer for electrophoresis, protein purification, and cell culture work—each application needing tight pH control for success. Its chemical make-up makes it less likely to react with metals or other ions floating around, so it often finds use where other buffers fall short.
BES stands as a colorless, crystalline solid—something you can hold, almost like kitchen salt, but a little softer to the touch. It dissolves nicely in water, which matters for quick mixing and reproducibility in lab prep. The compound’s sulfonic acid group steps in to keep the pH stable between 6.4 and 7.8. That range fits well with the needs of most biological tissues and proteins. It’s got a decent molecular weight at 213.27 g/mol, a melting point above 300°C, and won’t break down in normal lab settings. BES doesn’t absorb much UV at 260 or 280 nanometers, which means it won’t block the detection of nucleic acids or proteins in solution.
Suppliers ship BES as a powder, typically in bottles or large drums for anyone making big batches of buffer. Most bottles come with specs such as assay purity (usually above 99%), moisture content, and heavy metal limits clearly typed on the label. Labels include the chemical formula (C6H15NO5S), CAS number (10191-18-1), and warnings about safe handling. Regulatory compliance—REACH, RoHS, or local laws—gets stated too so users don’t run into trouble later. Information about shelf life, storage temperature, and compatibility with common reagents brings transparency that operators appreciate, especially in GLP labs.
Lab-scale production of BES starts from ethylene oxide and sulfur dioxide, passing through a few chemical steps under controlled conditions. The process begins with 2-aminoethanesulfonic acid, which reacts with ethylene oxide to attach the hydroxyethyl groups. A purification process—focusing on crystallization, followed by thorough washing—gets rid of side products and impurities. In most manufacturing plants, the focus falls on clean conditions, closed systems to avoid contamination, and routine batch testing to guarantee each lot meets technical specs. Every batch brings new learning, especially as scale increases or as customer standards change.
BES behaves with impressive stability. It won’t fall apart or react under standard storage, and precious biochemical samples stay protected. Scientists sometimes tweak the molecule, attaching different functional groups for use in customized affinity resins or covalently linking to dyes. BES forms stable salts with sodium or potassium, expanding compatibility with different applications. Chemical reactions mostly leave the buffer backbone alone, but work on the hydroxyl groups or the amine slot can add value for targeted needs, such as immobilizing enzymes or directing protein binding.
BES pops up under several names in catalogs and safety sheets. Its systematic name stands as 2-(Bis(2-Hydroxyethyl)Amino)Ethanesulfonic Acid, but research circles use BES, BES buffer, and sometimes even “Good’s buffer.” The sodium salt sometimes gets called BES-Na or BES Sodium, depending on the supplier. These aliases help researchers track down the same compound across global suppliers, ensuring results carry over from one lab to another, regardless of geography or preferred catalog.
Lab techs using BES stay alert, despite its generally favorable safety reputation. It rarely irritates skin or eyes, and isn’t volatile, but ingestion or massive inhalation is a non-starter—like any fine powder in a laboratory. Lab guides, MSDS sheets, and safety officers push gloves, splash goggles, and dust masks for anyone handling bulk material or mixing stock solutions. Regular training keeps accidents to a minimum, and fume hoods make up for surprises. Local laws, especially in shipping and waste disposal, require attention: BES, while not especially dangerous, can’t just go down the drain in every city. Care in use and disposal shows respect for coworkers and the environment.
BES lifts a heavy load in molecular biology labs. Protein purification, PCR buffers, electrophoresis gels, and enzyme assays often rely on it for the right pH. Researchers tend to pick BES when Tris or phosphate buffers add unwanted reactions or lead to metal binding problems. Its range near neutral pH makes it gentle on sensitive cells—neuron cultures or hybridoma cells, for example—where deviation can ruin months of work. Scientists also use it in the making of diagnostic kits and drug formulation research, where minor impurity or pH drift turns into major headaches. Those working on glycoprotein assays or nitrite/nitrate detection value its inertness, which keeps their readouts clean.
Scientists never really stop testing buffer systems. Work on BES focuses on understanding its reactivity under extreme conditions—high temperature, oxidative stress, or long-term storage. Some research explores ways to make BES less expensive, pushing for greener synthesis routes or reusing waste streams. In academia, teams develop derivatives or cross-link BES to make new types of gels for chromatography or slow-release drug systems. Each tweak gets trialed for biocompatibility and long-term stability. Partnerships between universities and buffer manufacturers lead to improved labeling, easier handling, and formulation tweaks that help labs meet reproducibility goals.
Past studies show BES carries a low toxicity risk, but no buffer earns a blank check. Testing goes into its effect on microbial systems, cultured cells, and sometimes even small animals, checking for cellular injury or changes in metabolic rate. Key findings suggest BES gets along well with common model organisms at concentrations used for buffer prep—no major mutagenic or teratogenic effects stand out. Caution stays in play, though. Chronic exposure data remains limited and nobody wants unexpected cumulative effects, especially as the world demands safer work environments. Labs build in controls to limit unnecessary exposure or inhalation, showing a careful approach to risk.
Interest in BES grows as precision medicine, single-cell genomics, and advanced biomaterials become mainstream. Labs need buffers that endure harsh purification steps, rapid temperature swings, and contact with sensitive proteins. BES brings reliability and chemical stability to the party, which helps it secure a place in automated workflows, high-throughput screening, and new diagnostic platforms. The market could shift as green chemistry demands push suppliers to find renewable raw materials or safer by-products. Research into buffer blends, hybrid materials, and nanotechnology points toward expansions of BES’s toolkit, supporting researchers in both public health and cutting-edge biotech. New needs trigger new solutions, so BES stands ready for further adaptation as science moves forward.
Step into any laboratory and you’ll spot bottles labeled with acronyms—BES stands out among them. Scientists rely on buffers all the time, not out of habit, but because good research depends on precise pH control. Without buffers such as BES, protein experiments veer off course, enzymes lose their punch, and even the most promising cell cultures start acting in unpredictable ways. My first months in a molecular biology lab taught me this lesson quickly: swap a buffer, witness weird results, and then scramble to track down the missing piece.
BES, or 2-(Bis(2-Hydroxyethyl)Amino)Ethanesulfonic Acid, became a go-to buffer for a reason. It covers a pH range spanning about 6.4 to 7.8, sitting right where many biochemical reactions happen in living systems. Many proteins sit at the mercy of their environment. If the conditions get too acidic or too basic, they misfold or stop working. BES keeps things steady, so experiments run true from start to finish.
BES doesn’t just blend into the background. Compared to the more common phosphate buffers, BES shows much less tendency to interfere with ionic reactions. This comes in handy during electrophoresis or studies involving calcium, magnesium, or other key ions. In my own hands, switching from phosphate to BES meant the difference between smeared, useless gel bands and crisp, readable data. Less interference translates to greater confidence in what you see under the microscope or in the spectrophotometer.
Researchers in environmental science, medicine, and biochemistry all reach for BES. For example, studies involving mitochondria run smoother, since BES helps keep the cell machinery’s pH at a realistic level. Cell cultures enjoy a more lifelike environment with BES compared to other artificial buffers, which sometimes stress out cells and produce misleading outcomes.
Clinical labs also often pick BES for diagnostic work, especially when tiny pH shifts can send test results off track. Stability is the word I hear most, and BES delivers it—even during those late-night assay runs when the lab thermostat swings high or low unexpectedly.
Like every chemical in science, BES brings its own complications. It costs more than some old-school buffer salts, and not every supplier stocks medical-grade material. Some labs stretch budgets with cheaper options, but those savings can fade after a few failed experiments.
The bigger issue for many scientists comes from oversight. Too many times, postdocs and grad students memorize recipes and pour without double-checking what their buffer might interact with. Skipping trial runs or skipping controls leads to wrong answers. This isn’t unique to BES, but its precise capabilities get wasted if folks don’t learn the quirks first.
Hands-on training turns buffer use from a rote task to a thoughtful process. Watching senior researchers measure out BES and calibrate pH meters taught me patience and respect for the chemicals we lean on every day. Best practices start at the bench: fresh solutions, clean glassware, and checking expiration dates as closely as one would in a home fridge.
Scientists who write detailed notes, track batches of buffer, and pay attention to how their BES performs help the whole team. Open discussions about success and failure, honest record-keeping, and a little curiosity keep the field moving forward. Choosing BES wisely means more than just following a protocol; it means understanding why that blue bottle matters, every single time.
BES buffer seems like just another clear solution on the shelf, but a lot can go sideways if it’s not stored right. I’ve seen some odd results myself just because someone left it out, thinking, “It’s fine, it’s just a buffer.” That’s rarely true. Science leaves little room for short cuts, and like a stubborn lock, things don’t fit together as they should when chemicals change composition, even slightly.
BES (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid) keeps its cool best at room temperature, away from sunlight and in tightly closed containers. Keeping the bottle out of the heat and not letting it dry up keeps the powder from caking or decomposing. While you won’t see smoke pouring out if you slip up, the real risk starts when the buffer starts pulling in moisture from humid air or—worse—gets contaminated. Every time moisture seeps into a bottle, the odds of mold or chemical breakdown increase. I’ve unboxed my share of clumpy powders and know that once it gets chunky, you might as well order a new batch.
We often think only light-sensitive chemicals need to stay hidden, but even sturdy buffers live longer away from bright light. Direct sunlight can sometimes lead to subtle changes over weeks. The change might not show up right away, but you’ll notice experiments don’t track like they used to. Over the years, I’ve learned not to cut corners and stash my BES on a bottom shelf, far from heat and bright spots. My experiments thank me, and so does my peace of mind.
Now about BES buffer solutions. I always prepare only what I need. If you’ve got some left over, pop it into the fridge (usually 2–8°C), well labeled, and screw the cap on tight. Use it up within a week if you can. The main aim here is to keep bacteria and fungi out and avoid evaporation that concentrates the solution. Filtration after preparation keeps microbes away a bit longer, but I’ve learned not to trust old buffer—if in doubt, mix fresh. It saves time in the long run, especially if your buffer hosts sensitive enzymes or cell cultures.
Keeping BES buffer in the right conditions actually changes scientific outcomes. If the buffer absorbs CO₂, the pH tends to drop. I remember a graduate project getting derailed for weeks because someone used BES that sat open on a bench. Data looked off, but there was no obvious error until we checked the buffer’s pH. Lab basics may seem like muscle memory after a while, but small mistakes pile up and end up wasting time and resources.
It always helps to train everyone who uses BES with hands-on storage demos. Red tape isn’t the issue—it’s just clear labeling, dating, storing away from moisture and sunlight, and throwing out anything that starts looking off or has been open too long. Reliable research starts from basics; one overlooked bottle of buffer can set back whole projects. Follow the routines that trusted labs use, and results almost always improve.
BES, or N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, often comes up during lab work that deals with biological reactions. Many scientists, including myself, have spent days trying to find the right buffer for an experiment—one that doesn't mess with protein activity or bend under temperature changes. BES offers an answer for certain projects, mainly thanks to its steady action around pH 7.
Getting the pH just right allows you to maintain the natural shape and charge state of molecules in your mix. The sweet spot for BES sits between 6.4 and 7.8, according to published literature. This range includes the physiological pH used in most animal tissues, which falls near 7.4. So, BES supports research that relies on mimicking what's happening inside living creatures, such as enzyme activity studies, protein purification, or cell culture work. I remember hauling out lists of Good’s buffers and narrowing it down just by asking: does it keep my protein stable? Anything too acidic or alkaline would ruin the day, no matter the fancy equipment on the bench.
In practice, researchers don’t pick chemicals for their names—they look at how each buffer keeps its pH under working conditions. Out in the real world, temperature swings or chemical reactions can nudge the pH value off course. BES holds up better than some alternatives, such as Tris, in environments where temperature changes fast or where certain ions come into play. For instance, it doesn’t interfere much with calcium or magnesium, so it can run quietly in biochemical experiments that measure their effects.
Even a stout buffer like BES creates its own set of hurdles. Some enzymes dislike the sulfonic acid group, refusing to work normally or winding down early. Folks have reported certain bacteria and cell lines showing odd growth patterns when BES concentrations creep above what’s recommended. Then, there’s always the financial side, since specialty buffers don’t come cheap compared to the classic phosphate set. You see this play out in smaller labs, where every cent matters and researchers often recycle or stretch what they can.
Fixing buffer headaches usually means more than reading a spec sheet. Some labs set up side-by-side experiments using both BES and another nearby buffer, such as HEPES, to check which one keeps proteins intact across the day. A few folks add stabilizers or tweak concentrations to minimize enzyme grumbling. Careful calibration with high-precision pH meters becomes critical, because a tiny drop in accuracy can send an experiment off the rails. In shared labs, communication takes priority: posting protocols, discussing what’s worked, and learning from experiments gone wrong. This saves time and costly mistakes for everyone working with BES.
Peer-reviewed studies and buffer manuals back up the pH range mentioned above. BES stands out for projects that demand stability close to neutral pH and need to avoid phosphate’s interference. Experienced researchers keep a close eye on details like temperature dependence and compatibility with biological molecules. Working with this buffer can mean fewer surprises down the line—as long as one respects its limits and leans on the hard-earned knowledge passed down in every well-run lab.
BES buffer, or N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, turns up on many lists for biological research. Designed to manage pH levels near neutral, BES shows up as a solid choice for biochemical reactions and electrophoresis. Sometimes, scientists consider using it in cell culture. Right here is where things get interesting: just because a buffer holds pH in the desired range doesn’t always mean it works out for living cells.
Cell culture isn’t just about keeping pH steady. Cells notice everything: osmolality, buffer composition, even minor contaminants. Most mammalian cells thrive with HEPES or bicarbonate based systems. These buffers have a long track record in supporting cell metabolism, growth, and survival. If you swap in BES for those, sometimes cell growth stalls out or weird changes start appearing in the cultures. The buffer’s performance can hinge on factors like concentration, temperature, or even media ingredients. Scientists have noted that at higher concentrations, sulfonic acid buffers such as BES can cause cytotoxicity and oxidative stress.
BES is stable, with low absorbance above 260 nm, which makes it handy in some protein-based applications. But the buffer can chelate certain metal ions, including calcium and magnesium. Cells actually rely on these ions for everything from structural support to enzyme activity. If BES soaks them up, cells may suffer. It’s not just theory — published accounts report cell morphology changes and less than impressive viability numbers after BES goes into culture media.
Multiple studies have measured BES against the workhorse buffers used in cell culture. In one widely cited experiment, Chinese hamster ovary (CHO) cells were grown in media containing BES, HEPES, and bicarbonate. CHO cells in BES buffer lost viability after a few days, even as those with HEPES or bicarbonate kept multiplying. The researchers traced the trouble to an interaction between BES and key nutrients, possibly worsened by breakdown products forming over time.
People working in labs sometimes face the urge to try out new buffers, hoping for better pH control or lower cost. Experience shows that swapping out core ingredients affects cell health in ways that only show up after hours or days. For long-term growth, buffers need to stay inert and avoid harming the cells. To this day, peer-reviewed safety data for BES in cell culture remains thin. Most companies offering media supplements avoid including BES by default.
Many who keep mammalian cultures stick with tried-and-true options. Bicarbonate buffers, with controlled CO2, give reliable pH stability while supporting energy metabolism. HEPES often steps in for non-CO2 incubators and live imaging setups. Both are accepted by regulatory agencies and supported by decades of data. BES, in contrast, is better left for protein or enzyme assays where living cells aren’t involved.
The importance of buffer selection goes beyond tradition. Good results depend on robust, well-documented components. Teams looking to change buffer systems have the responsibility to run side-by-side viability checks and consult toxicity studies. If data is missing, it’s smart to question whether adopting a different chemical saves any time in the end. Solid science comes from attention to detail, especially with live systems depending on every single ingredient poured into the dish.
BES buffer holds a solid spot in biological labs, especially during experiments involving proteins, DNA, or cell culture. Its chemical name is N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid. Many protocols choose BES because it keeps the pH stable, usually hovering around 7.15 at room temperature. I remember many late nights adjusting pH levels because a stable buffer can make or break a Western blot or cell transfection experiment.
A standard lab always keeps BES powder handy, along with 1N sodium hydroxide or hydrochloric acid to tweak the pH. Deionized water is a must for dissolving the BES, as it avoids extra ions that could mess with results. A magnetic stir bar, beaker, and digital scale round out the must-haves. Forgetting even one piece of this kit wastes time, and those who’ve dashed between rooms to borrow a pH meter know that frustration.
To prepare 1 liter of a 50 mM BES buffer, measure out 10.5 grams of BES powder. Pour this into a clean beaker. Add about 800 milliliters of deionized water—never the full volume yet—because the buffer will expand a bit once the powder dissolves and the pH is adjusted.
Mix the powder until it looks fully dissolved. If it clumps, some gentle warming can help, but don’t microwave it. Dissolving takes patience, especially if the powder’s fresh out of the fridge and clumping together. Experience says always use a magnetic stir bar and a stirring plate, especially for larger amounts.
Most researchers set BES buffer’s pH to 7.15, but some protocols request 6.8 or 7.5. Dip the calibrated pH meter probe in and start with small drops of NaOH to bring the pH up, or add HCl to bring it down. Stir constantly and go slow—overshooting on pH means more time wasted, more buffer lost correcting mistakes. I learned this the hard way, pushing the pH too high and watching expensive chemicals go down the drain. Always let the solution reach room temperature before making a final pH check.
Once the pH is spot on, pour the buffer into a graduated cylinder and add deionized water until you hit the full 1-liter mark. Lab notebooks should get a detailed note about the final molarity and pH, because trying to retrace steps weeks later without good records turns routine science into detective work.
Molarity means moles per liter. For BES, the molecular weight is about 213.2 g/mol. Using 10.5 grams in a liter of water gives 10.5/213.2 = 0.049 moles per liter, or 49 mM. Most labs round up and call it 50 mM, unless the experiment demands absolute precision.
Small mistakes in buffer preparation push experiments off course. Cells react in unexpected ways, or protein samples show strange bands. I’ve seen researchers trace failed data back to buffers prepared too quickly or with guessed measurements. Solid technique with BES buffer pays off by giving results that can actually be trusted. Keeping protocols clear and records detailed lifts science above guesswork—something every researcher owes to the community and themselves.
| Names | |
| Preferred IUPAC name | 2-[Bis(2-hydroxyethyl)amino]ethane-1-sulfonic acid |
| Other names |
N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid BES buffer BES free acid N,N-Bis(2-hydroxyethyl)taurine 2-[Bis(2-hydroxyethyl)amino]ethanesulfonic acid |
| Pronunciation | /ˈbɛs/ |
| Identifiers | |
| CAS Number | 10191-18-1 |
| Beilstein Reference | IV 4814 |
| ChEBI | CHEBI:41237 |
| ChEMBL | CHEMBL1132 |
| ChemSpider | 5734 |
| DrugBank | DB03743 |
| ECHA InfoCard | ECHA InfoCard: 03-2119980506-30-0000 |
| EC Number | BES’s EC Number is: 238-059-0 |
| Gmelin Reference | 93811 |
| KEGG | C02041 |
| MeSH | D020053 |
| PubChem CID | 23077 |
| RTECS number | DG1100000 |
| UNII | Y8AE5P02K6 |
| UN number | Not classified |
| CompTox Dashboard (EPA) | DTXSID3044255 |
| Properties | |
| Chemical formula | C6H15NO5S |
| Molar mass | 213.25 g/mol |
| Appearance | White crystalline powder |
| Odor | Odorless |
| Density | 0.287 g/cm³ |
| Solubility in water | soluble in water |
| log P | -3.8 |
| Vapor pressure | <1 hPa (25 °C) |
| Acidity (pKa) | 7.1 |
| Basicity (pKb) | 9.5 |
| Magnetic susceptibility (χ) | -6.4×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.523 |
| Viscosity | 3.8 cP (25°C, 1% in H2O) |
| Dipole moment | 5.24 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 274.1 J·mol⁻¹·K⁻¹ |
| Std enthalpy of combustion (ΔcH⦵298) | -3029 kJ/mol |
| Hazards | |
| Main hazards | Causes serious eye irritation. |
| GHS labelling | GHS07 Warning |
| Pictograms | ☣️🧪💧🧬 |
| Signal word | Warning |
| Precautionary statements | Precautionary statements: "P264 Wash ... thoroughly after handling. P280 Wear protective gloves/protective clothing/eye protection/face protection. |
| NFPA 704 (fire diamond) | 1*1*0 |
| Flash point | 140°C (284°F) |
| Autoignition temperature | 335 °C |
| Lethal dose or concentration | LD50 Oral Rat 7,100 mg/kg |
| LD50 (median dose) | LD50 (median dose): Mouse oral LD50 = 5,920 mg/kg |
| PEL (Permissible) | Not established |
| REL (Recommended) | 50 mM |
| Related compounds | |
| Related compounds |
BES sodium salt Bicine HEPES MES PIPES TES |
