A Guest Blog by Steve Pettit, Director Cell Culture Development, InVitria

We are often asked for a method to reduce or eliminate serum in culture. Below is an introduction on a method to reduce or eliminate serum in cell culture.

1. Use a base medium that supports serum-free growth. DMEM/F12 is a good base medium for most cell lines. DMEM, MEM and RPMI lack some of the micro-nutrients that are often required for serum-free growth. The F12 portion contains many of the micro-nutrients that cells need for serum-free growth. M199 is also a good base medium for some primary lines. These base media are available in certified animal-free from major media suppliers.
2. Use animal-free insulin-transferrin supplements to reduce serum. Once your cells have established growth in DMEM/F12 + serum, add 1x ITSE Animal-Free™ to the medium and slowly withdraw the serum (50% with each passage). Usually, serum can easily be reduced to 1-2% without any negative effect on cell growth. ITSE™ Animal-Free has rInsulin, rTransferrin, and Selenium. The transferrin will optimize the delivery of iron to your cells in reduced serum. Selenium and Insulin are required for by many cell types for cell growth.
3. Supplement with any line-specific growth factors. Some cells require line-specific growth factors. For example, stem cells often require protein factors; other lines require steroids, cholesterol, or other factors. Add these to your formulation as you withdraw the serum.
4. Enhance cell growth with rAlbumin Once your cells are growing at reduced serum levels, titrate Cellastim™ rAlbumin. Albumin enables or enhances serum-free growth. The optimum concentration of Cellastim varies between cell lines. One example of possible test dosages is 0.2, 0.5, 1, 2 g/L. Contact InVitria for more specific recommendations. Cells naturally receive nutrients and lipids through albumin. Albumin also removes toxins that can be detrimental to cell growth. Other growth factors such as Lacromin™ can be evaluated to further optimize serum-free growth.