Stem cells in the bone marrow express different molecular markers depending on whether they form bone or other tissue types ... basis of their morphology under the microscope.

Sure enough, under a microscope, it appeared that ... Wittmeyer have now found probable blood vessels, bone-building cells and connective tissue in another T. rex, in a theropod from Argentina ...

Bone marrow ... to be examined under a microscope. A bone marrow biopsy can help tell a physician how healthy a patient's bone marrow is and how it is producing new blood cells.