Serum-free media consist of appropriate nutritional and hormonal formulations that allow for cells to be cultured without the use of animal sera. There are many advantages to using serum-free media for cell culture, including increased consistency and productivity as well as easier purification and downstream processing. In addition, serum-free media can be formulated to contain combinations of growth factors that are selective for specific cell types. Serum-free media formulations are available for many primary cultures and cell lines, including recombinant protein-producing Chinese hamster ovary (CHO) lines, hybridoma cell lines, and cell lines acting as hosts for viral production (e.g., 293, VERO, MDCK, MDBK).;
Thermo Fisher Scientific is the world’s largest manufacturer of serum-free cell culture media and a leader in the development of innovative specialty media, including serum-free media options. Serum-free media (SFM) allow researchers to grow a specific cell type or perform a specific application in the absence of serum.
Simplify downstream protein purification with serum-free CHO media, optimized to support Chinese hamster ovary (CHO) cells. Select from chemically-defined, protein-free, and serum-free formulations as well as media for suspension or adherent cells. Browse CHO media catalog.
10743011,10743029,12490017,12490025,12681011,12681029,12052098,12052114,31033020Hybridoma media were developed to support hybridoma cell culture for antibody production. Choose from chemically-defined, protein-free, and serum-free formulations to improve your hybridoma cell culture.
11279023,12040077, 12045076, 12045084, 12372001, 12372003, 12372017, 12372025, 21340039Gibco Protein Expression Media are available in many formulations to support parental PER.C6, HEK 293, and HeLa cell growth in suspension culture. These protein expression media contain no components directly derived from human or animal sources. Explore all of our protein expression products at thermofisher.com/proteinexpression.
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When you're ready to switch to serum-free culture, we're ready to help. Whichever adaptation method you choose (sequential or conditioned medium), we strongly recommend that you always take these precautions:
Sequential adaptation is our preferred method for adapting cells to serum-free media (SFM media). This process tends to be easier on your cells as it allows the cells to adapt to the new media in several steps, with a typical conversion being:
| Passage 1 | 75% serum-supplemented medium:25% SFM |
|---|---|
| Passage 2 | 50% serum-supplemented medium:50% SFM |
| Passage 3 | 25% serum-supplemented medium:75% SFM |
| Passage 4 | 100% SFM |
In some cases, the change from 75% to 100% serum-free medium may be too stressful for your cells. Therefore, you may need to carry the cells for 2–3 passages in a 10% serum-supplemented medium: 90% SFM mixture.
Most cell lines can be considered fully adapted after 3 passages in 100% SFM media. Occasionally you may have trouble getting your cells past a certain step even before going to 100% SFM. If this happens, go back and passage the cells 2–3 times in the previous ratio of serum-supplemented media to serum-free media.
An alternate method for adaptation to SFM media involves the use of conditioned medium, which is medium the cells have been growing in for one full passage. If you choose this method, you can facilitate adaptation as follows:
| Passage 1 | 100% serum-supplemented medium |
|---|---|
| Passage 2 | 50% medium from passage 1:50% SFM |
| Passage 3 | 50% medium from passage 2:50% SFM |
| Passage 4 | 50% medium from passage 3:50% SFM |
| Passage 5 | 100% SFM |
Overall, cells cultured in serum-free media are more sensitive to extremes of pH, temperature, osmolality, mechanical forces, and enzyme treatment.
It is best not to use antibiotics in serum-free media. If you do, we recommend that you use 5- to 10-fold less than you would use in a serum-supplemented medium. This is because serum proteins tend to bind a certain amount of the antibiotic added, and without these serum proteins, the level of antibiotic may be toxic to certain cells.
Cells must be in the mid-logarithmic phase of growth with viability >90% prior to adaptation, and sequential adaptation may be necessary.
Seeding cultures at a higher density than normal at each passage during serum-free media adaptation may help the process. Because some percentage of cells may not survive in the new culture environment, having more cells present will increase the number of viable cells to further passage.
Cell clumping often occurs during adaptation to serum-free media. We recommend that you gently triturate the clumps to break them up when passaging cells.
It is not uncommon to see slight changes in cellular morphology during and after adaptation to serum-free media. As long as doubling times and viability remain good, slight changes in morphology should not be a reason for concern.
