If you’re a frequent buyer of mouse macrophages, you may have noticed a change in our product catalog. Starting in April 2019, we switched from peritoneal macrophages to bone marrow-derived macrophages; a small change for us that can have a big impact on your research.
Why the Change?
In short, we made the change because macrophages derived from bone marrow cells are much more pure than the peritoneal variety, giving researchers like you a better product for measuring macrophage activity.
What’s the Difference?
Getting more technical, there are other differences between these two types of mouse macrophages that prompted us to make the switch.
Peritoneal macrophages are found in the fluid within the peritoneal cavity between the abdominal wall and the organs it holds. Because of their location of origin, macrophages collected from the peritoneum are susceptible to contamination from granulocytes and lymphocytes.
With macrophages grown and differentiated from bone marrow, contamination is not an issue, meaning your bone marrow-derived macrophages are free of any other cell types that could cloud your results.
Because macrophages are an excellent source of many cytokines and chemokines that direct the immune response, a more pure sample will give you a greater number of these cell signaling proteins. We have measured IL-10, IL-12p70, TNFα, and IL-6 in the culture medium from macrophages stimulated in either LPS or poly I:C.
More About Bone Marrow-Derived Macrophages
Our mouse macrophages derived from bone marrow are functionally classified as M2 macrophages because they do not generate nitric oxide when stimulated with lipopolysaccharide (LPS). However, you can convert these to M1 macrophages by culturing with GM-CSF or IFNγ. You can then detect nitric oxide production following culture using a handy nitric oxide assay kit to quantitate the level of nitrites in the medium.
For more on the distinction between M1 and M2 macrophages, read this popular post.