Analysis of murine BM: specimen choice, sampling and processing.

Histologic analysis of murine BM is a necessary complement to flow cytometric or in vitro analysis.
Techniques to do this are well established in human hematopathology. A long tradition in experimental hematology focuses on femur and tibia as the source of BM. However, the thickness of the cortical bone and the often preferred use of the largest bone, the femur, for cell culture or flow leaved to the pathologist a hard specimen with little marrow.

The spine is an excellent source for BM analysis and is not used for any other type of analysis.

Procedure:

Once an anesthetized mouse is sacrified, correctly fixed to a board and opened up, remove all the visceral organs and most of the retroperitoneal tissue.
With a scalpel, make a deep incision in the left (A) and right (B) psoas muscles, as close to the spinal processes as you can. Then cut the spine at the level of the last ribs (C) and then at the pelvis (D). Now you can remove the whole spine, which will have a shiny whitish dorsal surface, two rough lateral sides where the muscles were and a ventral side with the vertrebral bodies.

You can fix the spine according to protocol and then decalcify either in acid decalcifyer (Cal-Ex, Fisher Diagnostics, CS510-10D) or EDTA.
After decalcification, slice the spine lenghtwise sagittally across the vertebral bodies and embed the two halves with the cut side facing the cutting plane.
You will have sections with ample marrow, bone cartilage and perispinal muscle to evaluate.