Bone Marrow
Definition
The fatty and haematopoietic tissue inside long bones such as the femur and tibia. Because it is enclosed in dense cortical bone, diatoms deposited there during ante-mortem hematogenous spread cannot diffuse back out, making it the preferred sampling site especially in decomposed remains.
- Sample source
- Long bones such as femur or tibia
- Enclosure
- Protected by dense cortical bone
- Advantage
- Resists post-mortem contamination and diffusion out
- Preferred use case
- Decomposed or skeletonised remains
Common questions
Why is bone marrow preferred over lung tissue for the diatom test in decomposed bodies?+
Lung tissue decomposes relatively quickly and can be contaminated by environmental diatoms after death, while marrow inside intact cortical bone stays protected far longer. In advanced decomposition, marrow may be the only tissue where diatoms deposited during life can still be reliably distinguished from post-mortem contamination.
How does the marrow diatom finding support a drowning determination?+
A positive finding of diatoms matching those in the recovery water, present inside intact bone marrow rather than only on external surfaces, supports that the diatoms entered the bloodstream through active respiration before death, which is harder to explain by passive post-mortem contamination alone.
Related terms
- Acid Digestion
- A laboratory preparation step in which concentrated mineral acids are used to destroy all organic tissue in a sample, leaving only acid-resistant...
- Ante-Mortem Drowning
- Drowning that occurs while the victim is still alive and the cardiopulmonary system is functioning. Active breathing and circulation are prerequisites for...
- Control Sample
- A water sample collected from the suspected drowning environment at or shortly after the time of body recovery. Its diatom assemblage is...
- Hematogenous Dissemination
- Spread of a substance via the bloodstream. In the diatom test, diatoms aspirated into the lungs during ante-mortem drowning enter pulmonary capillaries...
- Post-Mortem Immersion
- Placement of a body in water after death. Passive water entry into the upper airways and body cavities can carry diatoms into...