Species identification in forensic samples using the SPInDel approach: A GHEP-ISFG inter-laboratory collaborative...

Area of Science:

• Forensic science
• Molecular biology
• Genetics

Background:

• DNA analysis is crucial for species identification in forensics.
• Validated methods are needed for degraded and low-quality DNA samples.
• The Species Identification by Insertions/Deletions (SPInDel) method was recently developed.

Purpose of the Study:

• To test and validate the SPInDel method in a collaborative exercise.
• To assess the SPInDel method's performance with challenging forensic samples.
• To evaluate the SPInDel method's suitability for routine forensic casework.

Main Methods:

• A collaborative exercise involving 24 laboratories from 10 countries.
• Participants used the SPInDel kit to analyze 11 DNA samples of varying quality and mixtures.
• Species identification was based on numeric profiles from six mitochondrial ribosomal RNA (rRNA) gene regions.

Main Results:

• 22 out of 24 laboratories correctly identified all species.
• 98.8% of reported SPInDel profiles were accurate, including low DNA quantity and mixture samples.
• The SPInDel method demonstrated efficiency in mixture analysis and was easily implemented across different platforms.

Conclusions:

• The SPInDel method is a valid and efficient tool for species identification in forensic investigations.
• The method performs well with degraded DNA, mixtures, and low DNA amounts.
• SPInDel offers a reliable alternative to DNA sequencing for forensic species identification.