3-Morpholino propanesulfonic acid, better known by its abbreviation MOPS, stands out in laboratories across the world. Chemists recognize its straightforward formula: C7H15NO4S. It brings stability where it’s needed most—as a biological buffer. You can find it in the shape of white crystals, glistening pearls, dense solid flakes, or in powder form, each playing its part where pH precision counts. Its molecular weight clocks in at about 209.3 g/mol. The odor? Faint at most, letting the chemical do its work quietly. The density of solid MOPS rides around 1.45 g/cm³, a value that partners well with its role in solution-making. Water solubility is strong, so mixing up a MOPS solution in the lab doesn’t take much effort. With a melting point near 274°C (decomposition begins above this), labs can depend on stability across a wide range of conditions.
Each molecule of MOPS has a morpholine ring dedicated to maintaining pH, coupled with a sulfonic acid group tethered to a propane backbone. The structure itself isn’t just clever chemistry—it’s what gives MOPS its gentleness on living cells and its steadiness in buffering. Chemists who care about the tiniest detail dig into the molecular blueprint: there’s one sulfur atom, a nitrogen tucked inside the morpholine ring, and functional groups balanced for biological compatibility. This specificity anchors its place in protein biochemistry and cell culture work. MOPS holds its own, even in high precision environments where even small pH shifts can spoil months of research.
MOPS can arrive at your door in more than one form. Flakes, solid cakes, powder, and crystalline pearls all crop up in shipments. The texture and shape echo choices made in manufacturing and ease of handling. In my own work in the lab, reaching for MOPS as a powder saves time in preparation. On the other hand, flakes let you control weighing with just a little more accuracy—critical for making repeatable solutions. Availability as a solid gives storage flexibility, cutting waste and extending shelf-life. You might find large chemical warehouses selling drums of the stuff, locked down safely thanks to its steady physical state.
MOPS brings a backbone of stability due to its robust molecular property profile. Its pKa hovers around 7.2 at 25°C. That number means it keeps pH locked in a biological “sweet spot”, perfect for mammalian cell cultures and enzyme reactions. Handling is straightforward; you deal with a neutral, low-odor, water-loving material. Still, no chemical skips the safety step. MOPS typically tests negative for hazardous or toxic properties under most global regulations. I’ve never observed skin irritation, and material safety data confirms low reactivity. The CAS number 1132-61-2 and HS Code 29241900 unlock regulatory clarity for importers and logisticians moving drums from continent to continent.
Research-grade chemicals face a gauntlet of tough expectations. MOPS meets industries on the ground level. Its consistency allows bioengineers to support delicate cells, and its reliability keeps pharmaceutical processes on track. Diagnostic assay developers see it as the buffer that won’t skew test results. For raw material buyers, purity matters. High-quality batches stay below 0.01% impurity by strict HPLC analysis. If I buy from a new supplier, a simple pH test and UV profile spell out stories of how well the product stacks up to established brands.
Lab workers need to respect chemicals, MOPS included. Labels mark it as non-flammable, low risk for inhalation, and safe around standard plastics and glass. Store it dry, capped, away from acids and strong oxidizers. Humidity can clump the powder or flake forms, which is why I always reseal containers immediately after weighing. Proper labeling, adherence to regulations, and solid spill management make accidents unlikely. With the HS Code tied to international commerce, customs officials clear shipments without hassle, sidestepping complications reserved for more hazardous chemicals.
Some users weigh options between MOPS and alternatives like HEPES or MES, looking at charge, pKa range, and possible cellular effects. From years navigating buffer choices, MOPS consistently bridges the gap between affordability and tight pH control. Laboratories must keep sustainability and waste in the discussion. Used buffer solutions with MOPS should never head straight for the drain without understanding what’s mixed inside. Disposal strategies focus on the whole picture, merging environmental safety with regulatory mandates. These steps shape workflows that are rigorous and responsible, qualities tracked by experienced users and demanded by clients.
Those moments in research when experiments hinge on pH are common. Even minor slip-ups can toss out promising results. MOPS is one of the scaffolds modern science leans on, from life-saving pharmaceuticals to industrial enzyme research. I’ve relied on its consistency, watched how reliably it tracks with published specs, and seen firsthand the edge it brings to tight timelines. The chemical world is crowded with products promising wonders. The ones sticking around—like MOPS—earn that trust through robust specifications, clear structure, right molecular properties, and the ability to stand up to real-world scrutiny in density, physical state, safety, and global movement under the right HS code. That blend of reliability and practical traits is what keeps MOPS in steady demand, year in and year out.
