Cell Culture Media Quality Control Strategies | Corning

In many biology labs, everything revolves around the cell cultures. Providing cultures with high-quality culture media and sera is key to keeping cells healthy and growing well.

Without proper attention to cell culture media quality control, problems like contamination or slow cell growth can arise — and these problems can cause costly and time-consuming issues with experiments and procedures.

Here's how lab managers can ensure that media and sera are sourced, stored, and handled with quality in mind.

Sourcing and Quality Control of Cell Culture Media and Sera

Researchers purchasing sera and cell culture media need to be careful about where they get it from, first and foremost.

Fetal Bovine Serum Sourcing

Attention to serum sourcing is critical. Robert Padilla, a Field Application Scientist at Corning Life Sciences, explained that different countries have different levels of regulations for fetal bovine serum storage and production. This makes country of origin an important consideration for quality.

Request a Sample of Fetal Bovine Serum

Padilla said that serum from countries with fewer regulations, such as Mexico, often has higher variability in protein concentrations compared to serum from more regulated countries, like the United States. This variability can cause changes in cell growth and health, which is especially important in the production of therapeutic products. "For things like a GMP process, that [variation] can really impact scheduling and cause deviations that can make the end product unusable, [causing] an entire batch to be thrown out," Padilla said.

Look for sera that have low levels of endotoxin and hemoglobin. Low levels of these components are usually a sign of good quality and handling in the collection and separation process.

Laboratories should also conduct upstream testing to ensure they are purchasing a high-quality serum product that will meet their needs. Padilla advised contacting multiple vendors and performing small-scale tests with serum samples. "Reserve the lot for your entire process. That way, you can have consistency throughout a longer period of time."

To assist with this process, Corning offers lot reservation options for laboratories interested in testing serum before making a purchase.

Cell Culture Media Sourcing

Whether you plan to purchase powdered or ready-to-use liquid cell culture media, seek out a reputable source. As with serum, Padilla advises testing media from different sources. This is important because media from different vendors or different batches manufactured by less-reputable vendors can vary in the ratios of nutrients included in the media.

"Make sure the vendor you're buying your media from has a history of consistency . . . you don't want batch-to-batch variation," Padilla said. "That can impact your process and cause [loss of] money and resources along the way."

Media from less-reputable sources can also have issues with contamination or impurities, such as high salt content. To identify these problems, "You can put small samples of media in a plate and let it incubate. Sometimes, if they have too-high salt content, you can see crystallizing structures . . . or you can see contamination after a few days."

Preventing Media Contamination in the Lab

Contamination can be devastating to projects and can impact budgets and scheduling. Preventing contamination requires attention to lab cleanliness, procedures and habits, and medium and serum handling.

Bacteria and fungi are relatively common contaminants in laboratories. To keep them out of your media and cultures, ensure that basic hygiene and proper aseptic procedures are consistently implemented in your lab.

Keeping laboratory workspaces clutter-free can also help reduce contamination risks. "One thing I see with a lot of scientists is they'll have a whole bunch of things in the hood that they're working in — a lot of clutter. This can ruin the laminar flow that the biosafety cabinets provide, and that can introduce outside risk into your process."

Preventing cross-contamination between different cell lines is also extremely important. By some estimates, as many as 30% of cell lines used in laboratories may be misidentified, often due to cross-contamination with another cell line. "It's easy to mix up cell lines, and because a lot of them look similar, it's hard to identify without extensive testing," Padilla said. "You never want to work with two cell lines at the exact same time. You'll want to have different source media bottles and different incubators."

Supplies designated for use with specific cell lines should be clearly labeled. It's ideal to use different tissue culture hoods, but since this is often not a practical option, hoods should be cleaned well between different cell lines.

Padilla's overall advice for preventing contamination is to plan ahead and take the time you need. "Know what you're doing for the day. Get your items ready beforehand," he said. "If you're trying to rush and get your work done, and you have to go find stuff as you're trying to work in the hood, you start moving fast and that can introduce air into the biological safety cabinet that may [contain] bacterial or fungal contaminants."

Cutting corners on these steps is not worth the risk. "Getting a contamination in a process that's 60 days long... that's 60 days of work, products, and everything that goes into that."

A Guide to Understanding and Managing Cell Culture Contamination

Media and Serum Storage

Proper storage is another component of cell culture media quality control. In general, refer to the media or serum bottle or the manufacturer's website for storage and expiration date information.

Serum should be kept frozen when not in use because it loses potency over time when stored at 4°C. When taking out a new container of serum, if it won't be used within a week, thaw the serum overnight, make aliquots, and freeze the individual aliquots. Avoid unnecessary freeze-thaw cycles because they can also impact potency.

Powdered media can be stored at room temperature, but liquid media generally should be stored at 4°C or frozen for longer storage. After opening a bottle of media, excessive exposure to air can be recognized through color changes in the phenol red, a pH indicator included in most cell culture media. To extend media freshness, make aliquots so each container spends less time in contact with air. Another option, he said, is to close caps tightly and then use Parafilm to create a better seal over the top.

Label media and sera containers with the date on which they were thawed or opened.

How Corning Can Help

Corning offers a wide variety of high-quality cell culture media products to meet your cell culture needs. Corning's fetal bovine serum is sourced under a strictly controlled process that uses the highest quality standards. To find more information on media and sera sourcing, handling, and storage, visit Corning's website or get in touch with our product support representatives.