© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
ITS Liquid Media Supplement started gaining traction during the biotechnology surge of the 1970s and 80s. Scientists wanted defined, serum-free conditions that would help grow mammalian cells with less variability and fewer unknowns. Fetal bovine serum had its risks—batch variation, potential contamination, ethical debates. Researchers in university labs often spoke about headaches caused by unreliable serum lots. The world started looking for chemically defined alternatives, and ITS (Insulin-Transferrin-Selenium) arrived as a practical way to give basic nutrients without the wild-card factors. My own experience in tissue culture echoed this trend—switching from undefined supplements to ITS cut guesswork and made reproducible results much easier.
ITS comes as a clear liquid, typically added directly to culture media. The mixture supplies three key essentials: insulin to promote glucose uptake and cell survival, transferrin to deliver iron, and selenium as a critical trace element for enzyme function. Some variants include sodium selenite, others add extra growth factors. Anyone who's worried about keeping their cell lines healthy, contamination-free, and consistent often finds relief in a bottle of ITS.
ITS is typically colorless or has a faint yellow tinge, with a neutral pH that matches standard cell culture environments. Insulin in solution remains stable under refrigerated storage, and transferrin prevents iron-dependent oxidative stress. Selenium (as sodium selenite or selenious acid) acts in concentrations low enough to avoid toxicity but high enough to support selenoprotein synthesis. Mixing ITS into media rarely produces visible reactions—clarity stays intact, and pH shifts only slightly. Manufacturers fine-tune osmolarity, since small changes in salt balance can derail precious cell experiments.
Most ITS vials come with labels identifying batch, composition, storage conditions, and expiry. These details matter. In early graduate work, I kept a spreadsheet tracking ITS lots, and mismatched components once caused an experiment to fail, highlighting why clear labeling is more than bureaucracy. Standard ITS-1 contains 10 mg/L insulin, 5.5 mg/L transferrin, and 6.7 µg/L selenium, but some labs prefer to adjust ratios for their particular cell type. The package usually specifies whether human or bovine insulin has been used, which can influence experimental outcomes—a real consideration for anyone working with sensitive or immunologically picky cells.
Preparing ITS isn’t rocket science, but method matters. Typically, one mixes a 100x concentrated stock into basal media to achieve working concentration. I’ve learned from busted experiments that real-life mixing sometimes needs gentle swirling and not violent shaking; proteins foam and lose activity easily. Filtration through a 0.2-micron filter helps keep it sterile. Storage at -20°C preserves activity for months, but repeated freeze-thaw cycles degrade proteins. Old hands in the lab usually keep single-use aliquots to sidestep this issue.
ITS can survive mild temperature and pH variations, although insulin denatures if handled roughly. In some cases, people tweak the classic formula: replacing bovine proteins with recombinant human analogs eliminates animal-derived risks. Iron-free transferrin can be used for studies on metal uptake; selenium can switch between selenite and selenate forms. For custom applications, specific additives sometimes go hand-in-hand with ITS, from albumin to extra vitamins, reflecting the open-ended nature of cell culture research.
ITS goes by a few aliases, including “Insulin-Transferrin-Selenium Supplement,” “Serum Replacement Supplement,” or “Defined Supplement Solution.” Companies sometimes brand their own versions as 'ITS-X' or 'ITS-G', which usually means a tweak in protein source or an extra component. Veterans in life sciences know to always check the fine print. Cell growth can stall just because a supplier swapped out an ingredient, and troubleshooting those mysteries eats up valuable time.
Lab safety with ITS centers on careful storage and good sterile technique. Selenium salts deserve respect—they’re essential at trace levels but cross the line into toxicity even at modest overdoses. National guidelines require secure storage and documentation, and most institutions run regular audits. I once saw a junior researcher add concentrated ITS directly to cells, wiping out an entire experiment because of local toxicity. Proper training and clear protocols can prevent drama in the cell culture room.
ITS opens doors for serum-free culture of a wild range of cell lines—fibroblasts, epithelial cells, stem cells, even some hybridomas. Researchers lean on it for immunology, toxicity, virology, and metabolic studies. I’ve used ITS myself for stem cell cultures, reducing unknowns from animal serum. If you work in pharmacology, reducing animal-derived material cuts down on regulatory headaches and enhances data reliability when you move toward clinical applications. ITS isn’t universal; some fastidious primary cells demand more customization, but for many, this supplement means faster, more dependable research.
The past two decades have seen steady optimization of ITS, especially with the rise of recombinant biotechnology. Commercial firms now produce fully animal-free formulations, tailored for sensitive research like vaccine production or protein engineering. Regulatory agencies worldwide push for reduced animal components, so R&D now focuses on improving the consistency and performance of ITS in ever more demanding applications. Conversations at research conferences focus on not just supplementing growth, but also fine-tuning cellular signaling and metabolic flux—fields that lean heavily on improved media supplements like ITS.
Each ingredient in ITS has its own story with toxicity. Insulin can cause hypoglycemia in humans, but in cell culture, its risks tie to contamination or overdosage. Transferrin barely registers as a hazard at recommended levels, unless iron overload comes into play. Selenium’s narrow therapeutic window has long been recognized; chronic exposure risks oxidative damage. Toxicity studies in mice, rats, or in vitro cell systems continue to inform safer usage. Some labs monitor selenium concentrations in spent media, ensuring levels remain within the line between support and stress.
ITS once started as a workhorse for basic cell growth, but future directions look toward custom formulations. The growth of stem cell therapies, regenerative medicine, and complex biomanufacturing has raised the bar for supplement quality. Artificial intelligence and advanced analytics help dissect cell responses to media tweaks, meaning tomorrow’s ITS-like products could be highly tailored ‘media kits.’ Major labs and startups driven by breakthroughs in organoid culture and tissue engineering crave transparency over input materials. My own hunch leans toward fully synthetic, sequence-defined supplements as the gold standard for the next decade. That’s a future where what goes into cells is as clear and reproducible as the research results expected from them.
Anyone who’s spent time at a cell culture hood knows the sense of relief that comes from a reliable growth environment. Cells like to be picky. Too much sugar – they get lazy. Not enough iron – they slow down. When a project counts on predictable results, little details matter. This is where an ITS Liquid Media Supplement comes into play. It’s not just a bottle in the fridge; it’s a key to keeping tinkering and troubleshooting to a minimum.
ITS in “ITS Supplement” stands for insulin, transferrin, and selenium. Insulin helps cells take up glucose, giving them an energy boost that helps keep them proliferating. Transferrin, a glycoprotein, shuttles iron across the cell membrane, which cells need for just about everything involving metabolism or DNA. Selenium might not sound important, but this trace mineral knocks down oxidative stress, so cells don’t break down as quickly under normal growth conditions.
Labs used to use large amounts of fetal bovine serum or other animal-derived sera, but these can bring inconsistent results. Batch variation sometimes throws experiments off track. Animal-sourced components raise red flags too. There are concerns about pathogens, as well as ethical debates about animal welfare. With ITS supplement, researchers can maintain their cell cultures’ health and skip the unpredictable swings that come from using serum. That means less time repeating experiments – and less stress about what’s hiding in your media.
Some cells handle deprivation poorly. Stem cells, for example, don’t like surprises. They can start to differentiate, slow their growth, or just stop altogether if the formula isn’t dialed in right. ITS gives these cells just enough extra support. It strengthens reproducibility across cultures and across labs, which plays a big role in studies where results need to be compared.
Routine passaging and primary culture isolation get trickier without the buffer ITS brings. Projects for pharmaceuticals, vaccines, and gene therapies need cleaner systems. Cutting down on animal-based supplements keeps experiments aligned with regulatory requirements, especially for clinical-grade studies. ITS helps reduce outside variables. I’ve seen postdocs turn their attention away from explaining strange results and focus more on data that moves research ahead.
Most conversations about lab supplies focus on price or convenience. But choosing solutions like ITS touches on bigger issues – reproducibility, transparency, and ethics. The scientific community wants to trust the findings it builds on. Reducing unknown variables inside cell culture dishes brings everyone one step closer to results that stand up to scrutiny. Looking around any tissue culture room, there’s a quiet nod to the supplements that let researchers get on with the business of figuring things out, without guessing what’s actually feeding their cells.
Culturing cells outside the human body takes more than putting them in a dish with some nutrients. Most of the time, supplements boost the mix so the cells keep growing, behave as expected, and stay healthy. One of the most widely used additives is ITS Liquid Media Supplement. “ITS” stands for three important components: Insulin, Transferrin, and Selenium. These three make up the foundation, and they each play a different role in helping cells thrive.
Insulin helps cells absorb and use glucose. In cell culture, insulin isn’t just about energy. It keeps cells signaling properly. Decades ago, researchers realized cells (even those not from the pancreas) grow faster with small doses of insulin. By working directly with human stem cells in the lab, I've seen what happens if you skip it. Cells get sluggish. Some don’t even survive the week.
Scientific data backs this up. Studies from journals like Cell Culture Technology show cell yield jumping significantly when insulin is part of the cocktail. It encourages protein synthesis, aids cell survival, and replaces some of the growth signals that aren’t coming from blood serum.
Transferrin brings iron to the cells. Every cell needs a little iron to make enzymes, DNA, and proteins. Adding transferrin means cells don’t go scavenging their dish for stray iron atoms, which often aren’t around in the right form anyway. If the cells run low, growth slows and stress responses ramp up.
I’ve made the mistake of running cultures with media where iron is too low. The cells look fine for a few days, then things fall apart fast. Transferrin prevents that crash—iron gets delivered, but it isn’t free to float around and spark nasty chemical reactions.
This matters for labs going serum-free. Transferrin supplies the iron in a form cells know how to use, keeping the environment more predictable than relying on mysterious mix-ins from animal sera.
Selenium works in smaller amounts than the other two but comes with outsized importance. It serves as a core part of enzymes called glutathione peroxidases, helping destroy toxic peroxides before they build up and kill cells. Without selenium, oxidative stress jumps, and sensitive cells crash before they can be studied or used for therapy.
I’ve read in Nature Methods and seen in practice that even tiny tweaks in selenium concentration make big differences. Some of the best, cleanest cell lines in regenerative medicine come from cultures where selenium supplementation was tightly controlled.
Depending on the supplier, ITS supplements sometimes carry extra vitamins or trace metals, but the deep impact comes from insulin, transferrin, and selenium. These three have strong clinical and scientific backing. As researchers look for ways to drop animal products from lab processes altogether, the focus on these purified supplements only grows.
Switching to supplements like ITS removes one of the big mysteries of cell culture: variation from serum. Anyone who’s frozen out entire batches from one bad lot knows the value of predictability. Sticking with clear, well-studied inputs keeps experiments honest and makes scaling production realistic for cell therapies, biologics, or new vaccines.
In any lab where cells take center stage, folks count on certain supplements to keep experiments on track. ITS Liquid Media Supplement is one of those mainstays. It plays a crucial role delivering insulin, transferrin, and selenium—each one working quietly to nurture cells and cut back on serum reliance. Here’s the catch most don’t talk about: how you treat that little bottle after it arrives changes everything.
Direct exposure to room temperatures or a forgotten bottle under fluorescent lights can ruin more than just your plans for the week. Manufacturers don’t insist on cold storage for the fun of it. Each component inside an ITS mixture comes with its own shelf life. Even a chemist will tell you that insulin breaks down when left warm for too long. A refrigerated environment, best kept between 2°C and 8°C, helps slow down the breakdown of these sensitive molecules. Not every fridge in a lab stays consistent, so it’s smart to check temps with an old-fashioned thermometer rather than trust the sticker on the door.
Some might think tossing media supplements in the freezer adds months to their life, but that’s far from the truth for an ITS mix. Repeated freeze-thaw cycles, or skipping between extreme temperatures, can make proteins clump or fall out of solution. This can mean ruined media, wasted cells, and money down the drain. If the supplement turns cloudy, forms strange particles, or develops discoloration, something has gone wrong.
Opening and closing a supplement bottle too often, or leaving caps off while prepping media, lets in unwanted moisture and airborne microbes. Even trace amounts of contamination can spell trouble, especially since many ITS supplements don’t carry tough preservatives. Always use clean pipettes and avoid working open bottles longer than necessary. If the lab has more folks handling stocks, labeling open dates and keeping a usage log helps everyone keep better track.
Every time I see expired supplements tucked in the back of a crowded fridge, it reminds me how labs sometimes cut corners to save costs. But the risk isn’t worth it. Expired supplements show up in failed experiments with mysterious results or sickly cell lines. Manufacturers list the production and expiration dates for a reason. Pitch anything that goes past those dates, because fresh solutions push the odds in favor of reproducible data.
Treat media supplements with even more caution than your lunch. Keep them cold, always minimize how long the bottle stays open, and toss anything that looks off. If your lab shares stock solutions between teams, confine bottles to clearly marked shelves and train everyone to return bottles right away after use. Follow archival guidelines for opening dates, and if in doubt about the bottle’s history, swap it out. No one wants to blame a failed project on carelessness.
Good science relies on details others might skip. Treating your ITS Liquid Media Supplement with care forms just one link in the chain. But that link holds up every culture, experiment, and late-night result session. True expertise in any research setting means giving each piece of the process its fair share of attention—with storage at the top of the list.
Mixing chemicals or solutions is part of many people’s daily routines. Whether you’re cleaning your house, treating water, or working in a medical environment, the strength of what goes into the mix has direct results on how safe, powerful, or useful the end product turns out. Taking the time to figure out the recommended ratio between the concentrate and the solvent affects safety, cost, and results.
Too strong a solution often means trouble. Pouring in more concentrate might seem like a shortcut to better performance, but it usually leads to wasted product, damaged surfaces, or real harm to people. In hospitals, nurses live by labels and guidelines. The risk of burning skin or ruining equipment isn’t worth a hasty guess. On the other hand, skimping and over-diluting makes things ineffective—germs stay alive, stains linger, pests don’t die off. There’s been more than one occasion where someone ignored the label and ended up calling poison control or repainting a countertop. The right dilution becomes vital for everyone from kids with science kits to maintenance crews in skyscrapers.
Companies that make concentrated products don’t throw out numbers at random. Teams develop these ratios after hundreds of tests, checking for safety and efficiency in different situations. Standards from the Environmental Protection Agency and Centers for Disease Control guide these tests, setting rules for public health. If a bottle of bleach says one part to twenty for disinfecting floors, that’s based on killing bacteria without hurting pets or corroding surfaces. For pool chemicals, ratio guidelines mean the difference between clear water and an irritated rash.
No two products share the same formula or strength, so people can’t just use the same mix everywhere. I’ve seen friends misread directions and add pool shock to a pond at the same rate as a swimming pool, and every fish in that pond paid for it. Mistakes like these remind us that those small-font recommendations are there for a reason.
Getting the recommended concentration right doesn’t take special training. Read the label carefully. If the instructions seem unclear or missing, check reliable websites—manufacturers put digital documents online. A sturdy measuring cup makes a real difference; guessing amounts leads to trouble. If you're unsure, calling customer support often gets you a clear answer instead of guesswork. For cleaning around children or pets, leaning toward weaker solutions provides a first layer of safety.
Employers at bigger facilities usually train staff to use chemicals safely and stock proper charts and quick-reference guides. Investing a few minutes to double-check saves hours correcting mistakes. For products used in medicine or food handling, following professional guidelines does more than clean—it keeps people out of hospitals.
Clear, honest information keeps people, pets, and property safe. Good manufacturers use simple language, bold numbers, and FAQ sections so everyone can follow directions. Scannable QR codes now pull up video guides, taking the mystery out of mixing and improving safety. Sharing experiences online or with neighbors also helps—sometimes the real tip you need doesn’t come from a label, but a friend who learned a lesson the hard way.
The routine act of mixing solutions gets easier and safer with better labeling, smart technology, and straightforward education. Sticking to recommended concentrations saves money, prevents damage, and protects health. Instead of assuming, a pause to check instructions and ask questions gives the confidence to get the job done right.
Lots of folks in cell culture labs have reached for that familiar bottle marked “ITS Liquid Media Supplement.” It’s a staple, credited for keeping insulin-requiring cells happy without dragging out old-school serum. Still, for anyone concerned about animal content or strict reproducibility, knowing exactly what’s inside counts—it’s not just about growth, but the ethics and science behind what you’re growing.
ITS stands for insulin, transferrin, and selenium. Look closer at any reputable product label or supplier’s site and those three components normally appear. But the question nags: animal-free or not?
Insulin forms the grayest area. Older formulas sourced insulin from pigs or cows. Newer batches use recombinant human insulin, churned out by genetically engineered microbes. That means no animal content, as long as you check with the manufacturer that their process actually avoids animal byproducts at every stage. This matters for anyone culturing cells for vegan products, clinical research, or any project that sits under tight regulatory scrutiny. A lot of major suppliers promote “animal-origin free” versions, but they still expect the user to check documentation for trace contamination risk.
Transferrin poses a similar issue. Like insulin, it used to come from animal blood. Recombinant methods let scientists make human transferrin in yeast or plant systems, sidestepping animals altogether. Again, the burden sits on the buyer—ask for certificates stating the source and method, or trace the batch history before labeling anything “truly animal-free.”
Selenium is a mineral, easy enough to source in exactly the chemical form needed, without any chance of animal contamination. At least on that front, there’s no ambiguity.
Researchers crave consistency. Chemically defined means every ingredient, every concentration, is known and specified. That makes troubleshooting more straightforward, and lets labs compare results with real confidence.
If all three ITS ingredients come from recombinant or synthetic production—insulin, transferrin, and selenium—the supplement can be called chemically defined. The snag comes with additives or stabilizers in some brands. Take a look at full ingredient lists, not just the marketing brochures. Even things like buffer salts, preservatives, or carriers could cause problems if their origins aren’t clear. When growing human cells for clinical work, the smallest unknown can mean regulatory disaster.
Still, most big-name ITS supplements today market themselves as both “animal-free” and “chemically defined.” That’s not just hype. After the BSE scares and tight new FDA rules, suppliers overhauled production. In fact, several industry audits show supporting documentation has become the norm.
For me, cell culture is a daily grind—mix the media, seed the flask, cross fingers nothing contaminates. Every unexplained blip in a data trend wastes hours. Using media supplements with clear, transparent sourcing helps cut down on variables. Animal-free, chemically defined products make experiments repeatable. More importantly, for those of us working on food tech, stem cells, or therapeutic proteins, running a system free of hidden animal content isn’t just a bonus—it’s the bare minimum. Ethical customers, policymakers, and patients demand it. Even if some colleagues still grab the cheapest bottle, anyone aiming for clinical or commercial use will want to read every supporting document, because it truly matters.
Always demand transparency. Ask for the animal-origin free certification. Check supply chain documentation before trusting a product. Push suppliers to share lot-to-lot consistency data. Science and ethics both push the industry toward pure, recombinant, and chemically defined media supplements. It’s not only about ticking a regulatory box—it’s about bringing lab practices up to speed with current technology and public trust.
| Names | |
| Preferred IUPAC name | 1,2-Dithiolane-3-pentanoic acid |
| Other names |
ITS Liquid Media Supplement (100X) ITS Supplement Insulin-Transferrin-Selenium Supplement |
| Pronunciation | /aɪ-tiː-ɛs ˈlɪkwɪd ˈmiːdiə səˈplɪmənt/ |
| Identifiers | |
| CAS Number | '110745-81-8' |
| Beilstein Reference | 12092831 |
| ChEBI | CHEBI:60004 |
| ChEMBL | CHEMBL2223330 |
| ChemSpider | ChemSpider: 3493 |
| DrugBank | DB13953 |
| ECHA InfoCard | Ceritox ECHA InfoCard: "19-9249-7002773-13-0000 |
| EC Number | EC Number: 232-366-4 |
| Gmelin Reference | 1142032 |
| KEGG | C01352 |
| MeSH | Insulin; Transferrin; Selenium |
| PubChem CID | 73392057 |
| RTECS number | MD0905000 |
| UNII | CB9Z2IID0Y |
| UN number | UN1170 |
| CompTox Dashboard (EPA) | DB11259 |
| Properties | |
| Chemical formula | C6H8O6, C6H15NO3S, C6H13N3O4S |
| Molar mass | 236.33 g/mol |
| Appearance | Clear, orange liquid |
| Odor | Odorless |
| Density | 0.972 g/cm³ |
| Solubility in water | Soluble in water |
| log P | -2.13 |
| Basicity (pKb) | 8.2 |
| Refractive index (nD) | 1.336 to 1.340 |
| Viscosity | Viscous liquid |
| Dipole moment | 0 D |
| Pharmacology | |
| ATC code | V04CJ04 |
| Hazards | |
| Main hazards | May cause an allergic skin reaction. |
| GHS labelling | GHS labelling: Not classified as hazardous according to GHS. |
| Pictograms | Corrosive, Health Hazard, Exclamation Mark |
| Signal word | Warning |
| Hazard statements | H315, H319, H334 |
| Precautionary statements | P261, P264, P271, P272, P273, P280, P302+P352, P305+P351+P338, P333+P313, P337+P313, P362+P364 |
| NFPA 704 (fire diamond) | 0-0-0-Special |
| NIOSH | 80077 |
| PEL (Permissible) | 100 mL |
| REL (Recommended) | 5 mL/L |
| Related compounds | |
| Related compounds |
Insulin Transferrin Sodium selenite |
