Diatom Test
Definition
A laboratory test for ante-mortem submersion in which bone marrow (from sealed femur diaphysis) is acid-digested and the diatom species identified in the pellet are compared with species in the lung tissue and in the scene water sample. A species match constitutes positive evidence of ante-mortem aspiration.
- Primary evidence
- Confirms ante-mortem immersion (alive when submerged)
- Test method
- Microscopic examination of acid-digested tissue
- Specificity
- Species matching ties the body to the recovery-site water
Common questions
What does the diatom test actually detect?+
The test looks for microscopic algae called diatoms in body tissues, especially bone marrow. Forensic scientists acid-digest the tissue, then examine the pellet under a microscope to identify diatom species. Finding diatoms suggests the person inhaled water before death.
How does this confirm drowning specifically?+
The diatom species found in the body are compared with species in the water where the body was recovered. If the species match, it's strong evidence the person was alive when submerged and aspirated water into their lungs. Species mismatch or absence weakens the drowning diagnosis.
Which body tissues are tested?+
Bone marrow from the femur, sternum, or vertebral body is the most common source. Diatoms can also be found in lung tissue and distant organs like the liver and kidney after water aspiration.
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Explained in these topics
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