CDM HD, Chemically Defined Medium High Density Serum Replacement From FiberCell Systems, Inc.

CDM HD, Chemically Defined Medium High Density Serum Replacement From FiberCell Systems, Inc. (catalog number LC5800) is for use in cell culture basal medium in place of fetal calf serum. According to the manufacturer, it was specifically designed for the culture of cells at high density such as those used in the hollow fiber bioreactor systems that the company produces. In fact, it was optimized for use in their system. However, the manufacturer suggests that it can also be used in either spinner culture or roller culture. The product is chemically defined and protein-free with lot to lot consistency. Used at a concentration of 10% in basal medium, it is an economical alternative to serum. My use of CDM HD in medium (10%) for hybridoma cell culture provided an extremely successful alternative to using either serum or serum-free medium.

CDM HD comes in a dry powder that when mixed with water will make up one liter of 1X solution. The powder and the liquid must be stored at 4°C and the powder has a shelf of up to 6 months. When mixing, it is suggested to check that the pH is about 6.5. If not, adjust to 6.5 with 1N NaOH, making sure not to adjust higher than 6.5. A higher pH will prevent the powder from going into solution. Filter sterilize, do not autoclave, and then add the liquid to basal medium at a concentration of 10%. Due to the fact that CDM HD is protein-free, it does not contain cell attachment factors or cell membrane protecting surfactant (such as F60). When using in FiberCell Systems cartridges, just inoculate with 10% serum and then switch over to 10% CDM HD once growth is documented in the bioreactor. However, if growing in spinner flask or roller flask, a cell membrane protecting surfactant must be added. If using with adherent cells, then they must first be cultured in serum, and once attachment occurs in the flask, switched over to CDM HD.

The advantage of CDM HD is that since it is a protein-free, chemically defined formula, it simplifies purification. It contains none of the components of serum or “serum free” formulations. I noticed a big difference in cells grown in 10% CDM HD versus a “serum-free” medium. The cells I have used grow just as well in CDM HD as they do in serum, which has not been the case for serum free medium. There is no acclimation period, a direct acclimation is suggested by the manufacturer. I did not have to wean my cells off the serum; I changed the medium bottle used for the cells to my basal medium/10% CDM HD and did not see any decrease in the growth rate of the cells. CDM HD has worked for all the cell lines (murine, rat and human) I have grown in the FiberCell Systems’ hollow fiber bioreactor; I have also successfully used CDM HD in an adherent cell line cultured in flasks. Finally, because CDM HD is animal component free, regulatory compliance is simplified due to the lack of agents of unknown origin such as mycoplasma, prions or viruses that can impair pharmacologic use of the products derived from the cells. The supernatant is free of contaminants found in serum or serum-free medium.

My experience with CDM HD has been excellent even considering the one potential disadvantage to the downstream process of purification. The manufacturer cautions that since the formulation is protein-free and contains no ferritin that free iron levels will be higher than in standard mediums. This has not posed any interference with my purification using protein A. I have performed the purification with and without dialysis in the presence of a chelating agent and do not see that the ferritin from CDM HD poses any interference. However, it will be necessary to check your purification protocol and buffers. CDM HD does provide an excellent alternative to using fetal bovine serum or serum-free media and formulations and is worth trying.