Recording and analysing DNA from osteocytes in resin-embedded bone samples

Area of Science:

• Forensic Science
• Histology
• Molecular Biology

Background:

• Osteocytes are crucial for DNA profiling in bone samples.
• Resin embedding, used for preserving bone samples, inhibits DNA profiling.
• Current resin removal methods are time-consuming and use toxic chemicals.

Purpose of the Study:

• To develop a simplified process for resin removal from bone samples.
• To visualize the location and number of osteocyte nuclei.
• To assess DNA quality for short tandem repeat (STR) profiling.

Main Methods:

• Bone samples were stained with Diamond™ Nucleic Acids Dye (DD) and DAPI.
• Samples were processed using formalin-fixed or ethanol-preserved methods.
• Resin removal and visualization of nucleated osteocytes were performed.

Main Results:

• Nuclei location and number were clearly recorded via fluorescence.
• A strong correlation was found between stained nuclei count and DNA mass (r=0.873, p<1.21×10⁻¹⁰).
• Ethanol preservation yielded significantly higher quality DNA for STR profiling compared to formalin fixation (p<8.505×10⁻⁵).

Conclusions:

• The developed method simplifies resin removal and osteocyte visualization.
• Ethanol preservation is superior to formalin fixation for obtaining DNA suitable for STR profiling.
• This technique allows for STR profiling from resin-embedded bone samples within 24 hours.