4-Morpholinopropanesulphonic Acid, also known as MOPS, is a buffering agent widely used across laboratories and industry settings. People run into this compound when they focus on maintaining stable pH environments, especially in biological and biochemical research. MOPS steps up to the plate in these contexts because it keeps pH levels consistent, which lets scientists and technicians focus on gathering clean, repeatable data from sensitive enzymes, proteins, and cell cultures. Its structure makes it unique. The molecule combines a morpholine ring with a propanesulphonic acid group, which gives the material water solubility and strong buffering power.
Digging into the chemistry, 4-Morpholinopropanesulphonic Acid’s molecular formula is C7H15NO4S, and it has a molecular weight of 209.26 g/mol. The morpholine ring, tethered to a propanesulphonic acid group, creates a specific chemical footprint. The structure allows for heavy interaction with water molecules, helping it dissolve and perform as a buffer. The sulfonic acid group stays grounded and doesn’t evaporate or degrade quickly, which explains why buffer solutions made from MOPS keep their qualities over longer stretches of time.
MOPS usually appears as a white crystalline solid, sometimes as a fine powder or in small flakes. In the lab, the material feels fine and slightly slippery between finger tips, reminding people of other powdered chemical buffers. The density is about 1.22 g/cm³ at room temperature, so it settles heavily in containers and doesn’t float around the workspace, which helps reduce accidental spills. Some suppliers deal in pearls or larger crystals, but the core substance inside remains the same. In solution, MOPS dissolves clear and colorless in water, a feature that is crucial for spectrophotometric assays since no background color skews results. It can also come as a ready-made solution in laboratories, typically measured in mol/L concentrations, like 1M or 10X buffers.
Suppliers list purity data front and center, because impure buffer messes with results. Typical specifications put assay purity well above 99%. Measuring pH comes next, with the buffer range running from about 6.5 to 7.9, which fits common biological experiments. The HS Code for 4-Morpholinopropanesulphonic Acid commonly falls under 2934999099 for tracking across customs and trade records, letting buyers and sellers stay above board in international shipments. Testing for heavy metals, chloride, sulfate content, and insoluble material forms part of the standard quality report. These steps keep research outcomes clear and reproducible, a big deal for anyone who’s lost time to mysterious contamination before.
MOPS holds up well under regular lab conditions. It resists degradation in solid form, so it stores for years without clumping or yellowing, if kept dry and away from sunlight. Dissolved in water, the buffer’s steady hand comes from its sulfonic acid group, which does not volatilize or react quickly. Unlike organic acids or other less stable buffers, this one does not react with common metal ions or oxidizing agents in a way that throws off pH. The material keeps its shape, literally and chemically, even when heated gently as part of buffer preparation.
Working with 4-Morpholinopropanesulphonic Acid means understanding its safety profile. MOPS does not pose the hazards of true corrosive acids, but dust can irritate mucous membranes and the respiratory tract. Direct skin or eye contact can sting, so gloves and goggles pay off. Big spills call for sweeping the powder up gently, since fine dust floats easily but pulls in water from the air, becoming sticky. It's not a material known for acute toxicity, but inhaling or ingesting large quantities causes discomfort or mild health problems. Waste should go in chemical collection bins, not poured down drains, keeping safety top of mind for everyone in the facility. The substance usually ships as non-hazardous in most countries, but always check local rules before ordering or discarding.
In practice, MOPS enters facilities as a raw material for making custom buffer solutions at varied concentrations. It comes as a bag of white crystalline powder, sometimes pressed into pearls or flakes for larger-scale industrial users, or as granular solid to make weighing more exact. Chemical supply companies offer bottled solutions, especially necessary for those running aseptic or high-throughput labs. Some industries buy in bulk for manufacturing kits and diagnostics. Labs trust the purity and steadiness of solid MOPS buffers to keep their cell culture or enzymatic platforms running smoothly. Sometimes, researchers demand trace-metal certified MOPS, for especially sensitive experiments.
People in research, pharmaceuticals, and clinical labs rely on the specific buffering zone that MOPS provides for DNA, RNA, and protein-based work. If pH wobbles around during these tests, it’s easy to lose a whole day’s work or wind up with unreliable results. MOPS is part of a family of Good's buffers designed for biological safety, low membrane permeability, and low reactivity, which represents a shift from traditional buffers that were sometimes toxic or reactive with biological materials. Its invention widened the scope of what experiments could be done without buffer interference. In my own work, switching to higher-quality MOPS stopped unexplained color changes and loss of enzyme activity, making research a lot less frustrating.
One of the recurring problems with buffering agents like MOPS is sourcing high-purity material. Low-grade batches may carry contaminating ions, which can bind to proteins or enzymes in test tubes. This contamination creeps into experiments and hides in background noise, so people push for suppliers who provide certificates of analysis and purity by batch. Stockpiles kept improperly can cake or degrade after drawing in moisture from humid air, so using desiccators and airtight containers helps stretch the shelf life. Getting rid of buffer waste responsibly can pose a challenge, especially for large users. Some communities run chemical take-back programs, while manufacturers explore greener disposal or recycling methods. Every new chemistry, from drug development to diagnostics, asks for dependable, clean buffers. Working with reputable suppliers and practicing good lab hygiene make life simpler, both for accuracy and ethics.
