HOMOGENEOUS METHOD TO PREPARE SPERM DNA FROM SEXUAL ASSAULT CASES

Smart overview of the Invention

A novel method for isolating sperm DNA from swabs taken from sexual assault victims has been developed. This technique allows for the extraction of sperm DNA without the need to change buffers, which simplifies the process significantly. Non-sperm cells are first digested with an enzyme, and then another enzyme is introduced to degrade the victim's DNA while preserving the rapist's DNA. The elimination of centrifugation and filtration steps makes this method particularly advantageous in forensic science.

Current Challenges in Forensic Analysis

Forensic laboratories face a significant backlog of unprocessed rape evidence, with many swabs containing a mixture of victim and rapist DNA. Traditional methods for isolating sperm DNA involve multiple steps, including centrifugation and washing, which can be labor-intensive and result in sample loss. The complexity of these procedures makes automation difficult, highlighting the need for a more efficient approach.

Innovative Approach

The proposed method utilizes a combination of Triton X-100 and Proteinase K to resuspend cells from swabs effectively. This approach ensures that the subsequent degradation of non-sperm DNA can occur without changing buffers. The addition of DNAse I allows for the selective digestion of soluble DNA while maintaining the integrity of the sperm DNA, streamlining the extraction process significantly.

Process Steps

• Resuspension of swab cells using a buffer containing Triton X-100 and Proteinase K.
• Separation of victim's DNA by digesting it with DNAse I in the same buffer.
• Lysis of sperm cells to release sperm DNA into a compatible buffer for further purification.

Utility and Implications

This method is designed for high-throughput forensic analysis, enabling laboratories to process samples more efficiently. By reducing the complexity of sperm DNA isolation from mixed samples, this technique not only saves time but also minimizes the risk of losing valuable evidence during processing. The reliable results obtained from this method could significantly aid in identifying perpetrators of sexual assault.