MSC Qualified Fetal Bovine Serum
FBS is a major component needed for the culture of human mesenchymal stem cells. However, there are many unknown elements in FBS, such as signaling molecules, apoptotic factors, and nutrients. The variable concentration of these components can cause lot-to-lot variation, which means that some FBS lots do not support MSC culture.
|Clonal efficiency. The ability of individual MSCs to form colonies in culture (clonal efficiency) is very important in MSC research and has been shown to be highly dependent on the choice of FBS used in the medium. Clonal efficiency is measured using the CFU-f (colony-forming unit fibroblast) assay, which determines the ratio of the number of colonies formed to the initial number of plated cells. Figure 1 shows the superior clonal efficiency obtained using Invitrogen’s MSC-Qualified FBS compared to a competitor’s product.|
Figure 1 - Effect of FBS source on MSC clonal efficiency. (P <0.05; Student’s t-test).
|Expansion. Culture-expanded MSCs are used in a growing list of research applications including cell differentiation, gene expression, cell signaling, tissue remodeling, and tissue engineering.|
They are also being investigated for use in potential cell-based therapies in the field of regenerative medicine. The ability to expand cultures to higher densities or at faster rates can significantly reduce the cost of research and therapy. Invitrogen’s MSC-Qualified FBS can significantly improve MSC expansion characteristics (Figure 2).
Figure 2 - Effect of FBS source on MSC expansion. (P <0.05; Student’s t-test).
Differentiation. MSCs are multipotent, self-renewing, mesodermal- origin cells that can differentiate into a growing list of differentiated cell types. Traditionally, MSCs have been defined by their ability to differentiate into the three lineages of bone, cartilage, and fat. MSCs were shown to maintain their ability to differentiate into bone (Figure 3), chondrocytes (Figure 4), and adipocytes (Figure 5) when cultured using Invitrogen’s MSC-Qualified FBS.
|Figure 3 - Histological staining of osteogenic cultures growth in MSC-Qualified FBS. |
A. Plates were stained for alkaline phosphatase on day 14 using commercially available kits.
B. Plates were stained with Alizarin Red S on day 25 using standard staining techniques.
|Figure 4 - Histological staining of chondrogenic cultures growth in MSC-Qualified FBS. Chondrogenic differentiation medium supplemented with 10 ng/ml TGF β1, 50 nM ascorbic acid-2-phosphate, and 6.25 μg/ml insulin or control medium was then gently overlaid onto the cells and the plates were incubated for two weeks with re-feeding twice per week. The resulting pellet-like constructs were stained with Alcian Blue.|
Figure 5 - Histological staining of adipogenic cultures growth in MSC-Qualified FBS. For adipogenic induction, the medium was supplemented with 0.5 mM isobutyl-methylxanthine, 1 μM dexamethasone, 10 μM insulin, and 200 μM indomethacin. Cultures were re-fed two times per week with a complete change of medium. On day 7, cultures were fixed and stained with Oil Red O using standard staining methods.