Low copy number DNA profiling from isolated sperm using the aureka®-micromanipulation system.

Area of Science:

• Forensic Science
• Molecular Biology
• Cell Biology

Background:

• Accurate DNA profiling from limited biological samples is critical in forensic investigations.
• Existing methods for sperm isolation can be inefficient or lead to DNA degradation.
• Low-copy-number (LCN) DNA analysis presents challenges due to the small amount of available genetic material.

Purpose of the Study:

• To develop and validate a novel, sensitive technique for isolating single sperm cells from mixed cell populations.
• To enable reliable low-copy-number (LCN) short tandem repeat (STR) profiling using minimal sperm input.
• To present a comprehensive workflow from cell staining to STR analysis.

Main Methods:

• Utilized the aureka® micromanipulation system for precise cell manipulation.
• Employed HY-LITER™ fluorescent staining for distinguishing sperm from epithelial cells.
• Developed a microsphere picking technique for isolating individual sperm cells under fluorescence microscopy.

Main Results:

• Successfully isolated single sperm cells from mixtures containing sperm and epithelial cells.
• Achieved full short tandem repeat (STR) profiles from as few as 20 sperm cells.
• Demonstrated a sensitive and reliable method for LCN DNA profiling with no allelic drop out.

Conclusions:

• The aureka® system coupled with microsphere picking offers an effective solution for single sperm isolation.
• This technique significantly enhances the capability for LCN DNA profiling from challenging forensic samples.
• The presented protocol provides a robust workflow for sensitive genetic analysis from minimal sperm quantities.