Researchers hunted for strong, stable buffers to solve common pH headaches in biochemical experiments. Through trial and error in organic synthesis labs during the late 20th century, guanidinethiouronium ethanesulfonic acid rose as a direct answer for those who demanded precise, reliable chemical environments. The compound traces its lineage to the fusion of classic buffering groups – with guanidinium and ethanesulfonate roots – and was refined to withstand repeated sterilization, harsh reagent exposure, or long-term incubation. Its route from dusty publications to accepted lab staple shows how practical necessity and creative chemistry meet. Modern manufacturers rely on historical patents and public research to legitimize process improvements and guarantee authentic product through each batch.
Guanidinethiouronium ethanesulfonic acid serves as a buffering agent in sensitive biological systems, offering a balancing hand in everything from DNA extraction buffers to protein crystallization setups. Its stable performance, minimal background interference, and water solubility draw scientists who need predictable results. Though its catalog listing often includes synonyms like “GTESA” or “ETSA guanidinium salt,” the compound remains niche, finding loyal use among life science researchers who tire of generic, legacy reagents. Its adoption increased in labs dealing with recombinant protein purification, where pH drift wrecks precious samples and replaces discovery with frustration.
Typical GTESA presents as a crystalline white powder, sometimes drawing static in dry climates, but dissolves rapidly in deionized water. The molecular mass hovers around 238 g/mol, with a melting point above 200°C—which makes it handy when intense enzymatic reactions require brief high-temperature steps. The molecule’s dual nature, blending guanidino and sulfonic acid groups, lends it remarkable buffering capacity near physiological pH. Its ionic strength and chemical stability support reproducible assay conditions. Sulfonate users working near UV-vis detection thresholds appreciate its low absorbance, avoiding those messy blank corrections during spectrophotometry.
Suppliers highlight purity often measured by HPLC or NMR, frequently nearing 98% or higher. Moisture content checks, usually below 1.0%, guard against batch inconsistencies, especially critical for scale-up or GMP-adjacent research. Labels list hazardous designations under GHS, and batch certifications detail all relevant test results. Some vials include QR codes linking directly to MSDS, batch COA, and storage recommendations. Detailed lot tracking lets laboratories trace anomalies back to their source, and larger suppliers now audit manufacturing according to ISO 9001 and 13485 standards, prioritizing traceability over cheap volume. Academic labs and biotech companies value documentation—they need clear data for regulatory filings or scientific journals.
Lab synthesis leans on nucleophilic addition of guanidine derivatives to protected thiourea, followed by functionalization with ethanesulfonic acid chloride under mild conditions. Post-reaction washes strip impurities, and recrystallization brings the purity to the threshold needed for biomedical usage. Reactions often run in aqueous or mixed polar solvents, as completely dry conditions tend to generate polymerized byproducts. Some chemists streamline the final salt formation by pH titration, increasing efficiency for larger batches. Most facilities set up their preparation steps to avoid chlorinated solvents, meeting current environmental safety expectations. Automated reactors help scale the process while tightening batch-to-batch variation, and waste streams get neutralized by standard base washes before disposal protocols.
Specialists tinker with GTESA’s guanidino and sulfonate groups to develop derivatives with altered ionic properties or targeted delivery within living systems. Common paths include alkylation at the guanidino nitrogen or conversion of the ethane sulfonate to alternative anionic leaving groups for coupling reactions. Sometimes, chemists layer on radioisotopic labeling, using GTESA as a scaffold. These tailored versions target drug delivery or more precise protein-inhibition studies. Sulfonation patterns undergo minor adjustments to shift water affinity, enhancing compatibility with advanced diagnostic assays or higher-throughput screening kits. In the hands of an experienced team, these modifications pivot GTESA from a buffer to a critical probe or molecular tag.
Literature may call the compound GTESA, guanidinethiouronium 2-ethanesulfonate, or simply guanidinoethanesulfonic acid. Laboratory catalogs sometimes blend these titles, forcing users to check registry numbers or chemical structures to avoid costly mix-ups. Some companies brand their version with acronyms or supplier identifiers—these often carry identical chemical specifications in the fine print. Cross-referencing with existing application notes prevents confusion, especially in multi-institution research teams where uniform labeling rules still lag behind global commerce.
GTESA typically ranks as low hazard, but standard lab safety rules still apply. Contact with bare skin or mucous membranes can prompt irritation, especially for those with sensitive skin. Inhalation of dust risks respiratory discomfort, though fume hoods and glovebox setups provide ample control. Most data suggest storage in tightly sealed containers away from moisture keeps the product stable. Spill procedures include dilution with water, surface cleaning with mild detergent, and secure disposal in line with local chemical waste rules. Large-scale handlers commit to PPE, with appropriate ventilation and eyewash stations on standby. Manufacturers roll out detailed MSDS, and many university labs integrate chemical safety certification into onboarding for graduate students and interns alike.
Biotechnologists reach for GTESA while purifying proteins from bacterial or yeast lysates, taking advantage of its stable buffering over cycles of elution and wash. Structural biologists employ it in crystallography, coaxing fragile molecules to reveal atomic detail in diffraction studies. Diagnostics firms blend it into enzyme-linked assays, where small pH swings would otherwise trash experimental controls. Molecular biologists use it for nucleic acid stabilization, leaning on its compatibility with common enzymes. Pharmaceutical researchers explore GTESA for drug formulation and testing, especially for compounds prone to hydrolysis outside narrow pH lanes. Its low absorption profile reduces background in optical or fluorescent detection—a winning trait for high-throughput labs crunching thousands of samples daily.
Ongoing development projects turn up GTESA as a backbone in rapid diagnostic kits, giving field doctors accurate results outside the lab. Academic researchers chase after new derivatives, hoping to expand therapeutic options for rare disease models. Chemical engineers optimize production and seek green chemistry upgrades, experimenting with renewable-feedstock starting materials and closed-loop solvent recovery. Patent filings suggest interest in unique GTESA formulations for membrane protein stabilization—a notoriously hard challenge in drug discovery circles. Collaboration across disciplines pushes its role beyond simple buffering, introducing it as a starting point for custom reagent synthesis in mass spectrometry applications. Startups in the diagnostics sector closely follow these advances, hoping to unlock faster, more robust test platforms.
Primary toxicology records list low acute toxicity, with animal studies suggesting minor effects at high doses, mostly limited to gastrointestinal upset or mild sedation. Researchers track metabolites to assure no unexpected degradation products threaten downstream applications. Human cell culture studies show limited cytotoxicity at lab-use concentrations. Environmental fate tests indicate that sulfonate derivatives generally resist rapid biodegradation—posing minor but non-negligible concerns for large-scale industrial use. Leading safety analysts now advocate for expanded chronic toxicity and reproductive hazard screens to align chemical data with modern REACH guidelines. The compound’s low flammability and decent chemical inertness help mitigate risk in everyday settings, yet safe handling training remains mandatory.
The next decade will likely see guanidinethiouronium ethanesulfonic acid break out of its buffering background. Ongoing research points toward tailored derivatives that deliver drugs or stabilize fragile therapeutics, moving well into biopharma manufacturing. Environmental scientists advocate for greener synthesis, aiming at closed-loop solvent systems and enzyme-catalyzed processes to limit waste. Advanced analytics firms already test new GTESA-based sensors for field-ready diagnostics, a trend powered by growing demand for point-of-care screening in resource-challenged regions. Collaboration between chemical producers and medtech innovators aims to streamline regulatory approval, so new formulations find use faster. As more industries embrace digitized quality management, the global supply chain around specialized biochemicals like GTESA will tighten, with standardized documentation and end-to-end transparency expected across suppliers, from university labs to biomanufacturing giants.
It’s easy to get lost in the dense jungle of chemical names. Guanidinethiouronium ethanesulfonic acid, often known by scientists as GES, probably doesn’t sound familiar to most people. But if you spend time in a research lab, especially one focused on biology or chemistry, this compound shows up more often than many might guess. What makes it so useful? Many labs depend on it for experiments that deal with proteins and enzymes, key building blocks of life.
GES comes up a lot during protein purification, especially when researchers prepare samples for analysis. In the world of protein science, it’s not enough just to have a sample; that sample has to be in a stable environment, or else all the hard work collecting it could go to waste. This acid helps create such an environment. Its primary role is acting as a zwitterionic buffer, which means it can maintain a stable pH—I’ve learned the hard way how a slight shift in pH can skew the results in enzyme assays or protein isolation methods. It doesn’t react much with the proteins being studied. Instead, it keeps everything steady so that researchers see what’s really happening with their sample, not what pH swings might introduce.
Life at the molecular level depends on stable surroundings. Most proteins only behave as expected inside a narrow pH range. Even common tasks—say, studying enzyme activity—often fall apart if the buffer can’t absorb acid or base changes. Out in the real world, I’ve worked alongside scientists frustrated with buffers that failed to do their job. GES brings welcome stability, especially in situations where other buffers are too basic or acidic for the comfort of sensitive enzymes. Its structure lets it soak up changes without interfering with the reactions themselves. For this reason, it often takes the place of more volatile candidates in experiments involving protein characterization, enzyme kinetics, and electrophoresis.
Published research highlights several benefits, including GES’s ability to stay out of the way during complicated experiments. For example, studies in protein crystallography have used it to prevent protein denaturation. This goes beyond theory; many peer-reviewed journals note that its presence keeps protein shapes intact, which matters if your whole project depends on seeing how these molecules fold and interact. Handling GES in the lab does mean paying attention to details—a lesson not every newcomer remembers until it’s too late. Always weigh out chemicals with care, avoid inhaling powders, and keep good records to track exactly what went into the buffer solution. GES isn’t toxic in small lab amounts, but taking precautions never hurts.
While GES delivers a lot for the workbench scientist, some labs haven’t caught on yet to its benefits, often sticking with buffers that don’t always fit their needs. Sharing results and insisting on transparent reporting in research can spread knowledge about such compounds. Vendors can do a better job of explaining the pros and potential pitfalls, not just listing it alongside dozens of others in catalogs. Lab safety officers should walk through proper handling and disposal, as chemical waste streams grow with more advanced research. Training and education matter as the foundation for safe and effective use. With the right awareness, GES stands to take its deserved place among the tools that help unlock biological mysteries.
People often ask about the basic makeup of complex chemical compounds. Guanidinethiouronium ethanesulfonic acid doesn’t always make headlines, but understanding its formula matters for anyone working in chemistry, especially in labs focused on molecular biology or buffer systems. Naming conventions can be intimidating, but spotting the patterns in these names opens doors for better experimental design and troubleshooting.
The name “guanidinethiouronium ethanesulfonic acid” looks intimidating, though it becomes clearer once broken down. On one side, there’s guanidinethiouronium, a compound that combines guanidine and thiourea. On the other, ethanesulfonic acid, well-known for its role in buffer solutions due to its strong acid nature. Connect them, and now you’re talking about a multi-functional molecule often used to adjust pH or enhance solubility.
The formula for guanidine is CH5N3; for thiourea, it’s CH4N2S. Ethanesulfonic acid, a backbone in many buffer systems, comes as C2H6O3S. Combine them in the right stoichiometric ratios, accounting for charge balance and molecular stability, and you arrive at the full formula: C3H12N4S2O3. Some reference sources might list it more granularly, depending on ionization or solvated states, but this serves as the widely accepted backbone.
Misidentifying a formula in the lab can tank an entire experiment. I’ve seen time and again how a single wrong subscript or missed hydrogen scrambles results, wastes resources, and messes up grant timelines. Exact data isn’t just for thoroughness—it’s for reproducibility and trust. Labs that double-check their formulas gain a reputation for reliability, while those that cut corners suffer setbacks. Journals flag errors, collaborators lose faith, and those running large multi-center studies struggle to keep protocols synced.
Crystal structure analysis, elemental analysis, and spectrum data all point toward the same formula when labs prep pure guanidinethiouronium ethanesulfonic acid. Industry publications, such as the Merck Index and peer-reviewed journals, converge on the C3H12N4S2O3 description. Some journals detail the compound’s protonation state or note water of crystallization, but core composition remains constant. The research community benefits from universal agreement about naming and composition, especially in specialty chemicals used for biological buffers.
Fixing these knowledge gaps comes through training and referencing solid, trustworthy resources. I keep a lab notebook that lists chemical formulas for every compound I touch. Students who follow suit dodge preventable errors and learn to spot inconsistencies before they hit “submit” on a report or paper. Companies making reagents can support this by printing clear chemical formulas right on product labels. Professional organizations, like IUPAC, play a role by enforcing naming standards and publishing data sheets that cut through confusion. With these habits, the cycle of mix-ups breaks down, improving outcomes across the board.
Guanidinethiouronium ethanesulfonic acid—a mouthful, sure, but in practical terms, it’s another specialty chemical that shows up in research settings, labs hustling to solve complex problems, and sometimes in scale-up environments. Every experienced chemist and lab technician learns to respect a compound’s unique quirks, especially when it comes to storage. Too many stories start with a bottle kept on the wrong shelf and end with ruined results, lost money, or a safety scare.
This compound draws real attention because it’s both highly hygroscopic and reactive. Leave it uncapped on a bench, moisture in the air turns it clumpy within hours. I’ve worked in research environments where a small slip—forgetting a desiccator or not noticing a damaged cap—transforms powders into useless bricks. People think dry areas are enough, but lab air can change fast, especially in crowded chemistry hoods or old buildings where HVAC systems fail to keep humidity steady. That’s why chemical-grade desiccators or oven-dried cabinet storage become the gold standard here.
High-purity chemicals often come in sturdy, sealable containers for a reason. Air leaks, loose caps, or even ordinary plastic bottles risk contamination and moisture absorption. Based on hands-on practice, switching bottles or “borrowing” a bit of reagent without proper resealing usually causes headaches for the next user and can compromise the whole supply. Glass always outperforms plastic for reactivity problems; screw caps with inner seals add reliable protection.
Temperatures should stay steady and cool. Experience shows sunny windowsills, benches near radiators, or top-of-fridge spots all shift the chemical’s state over time. Targeting a room-temperature range, away from any direct heat, preserves both purity and performance. For really long-term projects, a refrigerator comes into play—though condensation risk rises, so chemical-safe fridges and tightly sealed bags or containers matter more than the actual number on the dial.
Mislabeling has tripped up top-tier labs more times than anyone admits. The human factor in chemical management often goes overlooked until a mistake ruins hours of work or sparks a scramble to contact emergency services. Clear writing, dates for opening and re-sealing, expiry reminders, and the hazard codes (including those unique to strong acids) keep every team member on the same page. I’ve seen good labeling streamline audits and prevent exposures in high-stress scenarios, especially for newer staff or students who might not know every bottle by sight.
Cross-contamination turns the storage shelf into a minefield. Chemicals sharing a space can interact in small but disastrous ways—vapors, trace splashes, or mistaken scoops. Separate this acid from strong oxidizers, bases, and anything organic that can react. Investing in labeled secondary containment bins—something anyone with a few years in a busy lab can vouch for—spares everyone from accident reports and the heartbreak of ruined experiments. Clean, compartmentalized storage proves its worth again and again.
Training isn’t just a box to tick. Keeping up with best practices, periodic checks, and real-world drills should be routine. In the labs where I’ve worked, senior researchers led by example: they didn’t just remind people to check bottles or desiccators, they inspected stocks themselves. This attitude stops accidents before they begin. Guanidinethiouronium ethanesulfonic acid reminds us that no chemical ever deserves routine treatment—respect, clear habits, and a healthy dose of diligence keep both the science sharp and the people safe.
Guanidinethiouronium ethanesulfonic acid doesn’t show up in everyday conversations or even in most science classes. Only researchers or industrial chemists usually encounter it. So, talk of hazard or toxicity tends to set off some alarm bells—but the real answer comes down to the facts around handling and exposure.
Chemicals with names like this rarely get public attention unless they pose danger or offer some unique benefit. Lab guidelines often separate chemicals into broad risk classes before clear evidence is available for rare compounds. That leaves plenty of uncertainty, prompting questions like “Is it safe to touch, breathe, or work around?” Experience in research settings offers some clues.
Over years working in labs, I’ve seen protocols flag this compound as an “irritant”—the sort that can cause redness on the skin, tearing in the eyes, or sneezing if dust flies up. The safety data I’ve reviewed lists it as harmful if swallowed, with strong advice to avoid direct contact with skin or eyes. Para-lab experience offers a practical insight: gloves and goggles, routine for many compounds, make good sense here. Few recorded accidents point toward a low risk of serious toxicity, but no chemical should be underestimated.
Disposal also deserves a mention. Responsible facilities collect compounds like this in dedicated chemical waste, then treat or incinerate them according to national standards. Waterways and landfills have no place as dumping grounds, a fact highlighted by local regulations. That moves the focus from personal risk to community and environmental responsibility.
Published toxicology work covers this compound sparsely, with some animal studies indicating moderate acute oral toxicity. Lab rats, often the first to “test” new compounds, showed warning signs at high exposures but did not always succumb at typical lab concentrations. Sources like the European Chemicals Agency stress the lack of long-term health data. What’s clear: inhalation, ingestion, or skin absorption should be avoided.
Chemical safety sheets from reputable suppliers repeat the same lines. Avoid eating, drinking, or smoking in work areas. Immediately wash off splashes. Seek medical attention for accidental exposure. Less is known about chronic exposure, making extra caution wise.
Some people shrug off chemical hazards until a spill or reaction goes wrong. That attitude ignores hundreds of stories where quick thinking and basic gear stopped a bad situation from becoming tragic. Labs run best with a mix of experience, clear rules, and up-to-date data. Respirators, gloves, and splash goggles turn worst-case scenarios into routine training exercises.
On the policy side, clearer reporting and open databases could help both professionals and the general public. Even chemicals used by handfuls of researchers shouldn’t escape labeling or oversight. Easy-to-read instructions—posted right near the bottle—work better than a stack of unread manuals.
Chemical safety relies on more than government regulation or research. Every user makes small decisions that add up—choosing a mask, tracking chemical inventory, filing an incident report. Even the rarest compounds deserve respect, since no job or project is worth a lifetime of health problems. Guanidinethiouronium ethanesulfonic acid seldom lands in the headlines, but the steps needed to handle it safely underline a bigger lesson: science moves forward when people put safety and clear information above convenience or habit.
Solubility tells a deeper story about a chemical than most labels suggest. Guanidinethiouronium ethanesulfonic acid isn’t a household name, but in research labs and biochemical work, its performance depends on how it mixes with common solvents. Ignoring solubility is like ignoring the fuel in an engine—it won’t work, no matter how fancy the car.
Most people working with this compound go straight to water. Dissolving guanidinethiouronium ethanesulfonic acid gets fast results in water at room temperature, thanks to the combination of guanidine and sulfonic acid groups. Both love forming hydrogen bonds, which is why you see rapid dispersion and a clear solution in minutes. That means labs can prep buffers and internal standards without fuss—results depend less on technique, more on the actual science.
Not all solvents work the same way, though. Ethanol, for example, manages only a limited solubility. Mixing the powder into ethanol leaves undissolved bits floating at the bottom. Here’s my take: the strong ionic nature of this molecule plays a huge role. Its guanidine and sulfonic acid moieties thrive on water’s polarity, but fail to mingle as freely in solvents with weaker hydrogen bonding.
I’ve seen researchers wrestle with solubility by adjusting pH. Adding a little acid or base tweaks the protonation state of the guanidinium group. Get the balance right and you boost solubility, but overshoot and aggregation becomes a problem. From my own time in graduate school, what worked best was patience—a slow increase in temperature alongside gentle stirring. Heating a solution gently up to 40°C or so speeds things up dramatically.
Running quick tests with different pH buffers and keeping an eye on cloudiness or any settling gave clues to what really worked. In my hands, near-neutral or slightly acidic pH made for the cleanest dissolutions, especially when prepping for biochemical assays.
People working in biochemistry care about repeatability. If a buffer recipe calls for guanidinethiouronium ethanesulfonic acid, a clear solution today means confidence tomorrow. Journal articles back this up—solubility over 1g/mL in water at room temperature shows up in several synthesis and protein extraction protocols.
Production-scale chemistry faces a different challenge. Solubility checks become quality control. No one wants batch waste or delays because the powder won’t dissolve. Manufacturers often rely on analytical-grade water with trace-level impurities filtered out. A little contamination, even from tap water, can shift the balance and clog up the works.
Because everything starts with dissolving, improving formulation processes can save time and money. Filtering water, pre-warming the solvent, and using gentle vortex mixing cut down on undissolved residue. For teams stuck with stubborn clumping, checking water purity, adjusting pH slowly, and keeping records of every tweak help nail down what works. These small moves, backed by direct observations and peer-reviewed data, mark the difference between frustration and steady workflow.
Guanidinethiouronium ethanesulfonic acid dissolves quickly under the right conditions and stalls under the wrong ones. Paying attention pays off, whether the goal is a reliable buffer or a clean production run. Respecting the basics of solubility makes for strong science—and less guesswork.
| Names | |
| Preferred IUPAC name | 2-(guanidinoiminomethylamino)ethane-1-sulfonic acid |
| Other names |
GES Guanidine Ethanesulfonic Acid Guanidinoethanesulfonic acid |
| Pronunciation | /ɡwəˌnɪdɪniˌθaɪjuˈrɒniəm iˌθeɪnsʌlˈfɒnɪk ˈæsɪd/ |
| Identifiers | |
| CAS Number | 5894-99-5 |
| 3D model (JSmol) | `C1(=NC(=S)N)NCCS(=O)(=O)O` |
| Beilstein Reference | 146471 |
| ChEBI | CHEBI:61448 |
| ChEMBL | CHEMBL1209317 |
| ChemSpider | 23071470 |
| DrugBank | DB04256 |
| ECHA InfoCard | 03c2f0a5-a2e1-4ef9-9194-6680a7c770f8 |
| EC Number | 68187-42-8 |
| Gmelin Reference | 86087 |
| KEGG | C18713 |
| MeSH | D016615 |
| PubChem CID | 444021 |
| RTECS number | YS9800000 |
| UNII | 4RGM5N31CZ |
| CompTox Dashboard (EPA) | DTXSID7045131 |
| Properties | |
| Chemical formula | C4H14N4O3S2 |
| Molar mass | 274.36 g/mol |
| Appearance | White to off-white crystalline powder |
| Odor | Odorless |
| Density | 1.50 g/cm³ |
| Solubility in water | Soluble in water |
| log P | -4.3 |
| Vapor pressure | Negligible |
| Acidity (pKa) | 1.00 |
| Basicity (pKb) | pKb ≈ 1.3 |
| Magnetic susceptibility (χ) | -64.2·10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.570 |
| Dipole moment | 6.75 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 308.6 J·mol⁻¹·K⁻¹ |
| Pharmacology | |
| ATC code | C04AX31 |
| Hazards | |
| Main hazards | Harmful if swallowed, causes serious eye irritation |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS05,GHS07 |
| Signal word | Warning |
| Hazard statements | H302 + H312 + H332: Harmful if swallowed, in contact with skin or if inhaled. |
| Precautionary statements | P264, P270, P301+P312, P330 |
| NFPA 704 (fire diamond) | NFPA 704: 2-1-0 |
| Lethal dose or concentration | LD50 Oral Rat 590 mg/kg |
| LD50 (median dose) | LD50: 50 mg/kg (intravenous, mouse) |
| NIOSH | SGK888 |
| PEL (Permissible) | Not Established |
| REL (Recommended) | Not Established |
| Related compounds | |
| Related compounds |
Guanidinium Thiourea Ethanolamine Sulfonic acid MES buffer |
