PCR-based identification of drowning: four case reports

Area of Science:

• Forensic Science
• Molecular Biology
• Environmental Science

Background:

• Diagnosing drowning is challenging due to non-specific physical signs.
• The conventional diatom test can produce false-negative results, especially in waters with low diatom counts.
• There is a need for more reliable methods to confirm drowning in forensic investigations.

Observation:

• This study investigated a polymerase chain reaction (PCR)-based method for detecting phytoplankton DNA.
• DNA was extracted from postmortem spleen tissues and water samples from drowning sites.
• Samples were analyzed using primers specific to algae (diatoms, green algae) and cyanobacteria.

Findings:

• Multiple drowning cases with negative diatom tests were identified.
• The presence of phytoplankton DNA, detected via PCR, supported the autopsy diagnosis of drowning.
• This method proved effective even when diatoms were not visibly detected in samples.

Implications:

• The PCR-based detection of phytoplankton DNA offers a promising supplemental tool for drowning diagnosis.
• This molecular technique can enhance the accuracy of forensic investigations in suspected drowning cases.
• Further consideration of PCR as an adjunct to the diatom test is warranted for improved diagnostic capabilities.