Enhancement of fingermarks and visualizing DNA

Area of Science:

• Forensic Science
• Molecular Biology
• Biochemistry

Background:

• Latent DNA detection is crucial in forensic investigations.
• Diamond™ Nucleic Acid Dye (DD) offers a novel method for visualizing DNA on various substrates.
• Assessing compatibility with standard fingerprint enhancement techniques is essential for practical application.

Purpose of the Study:

• To evaluate the compatibility of Diamond™ Nucleic Acid Dye (DD) staining with common latent fingerprint enhancement methods.
• To determine if DD staining affects subsequent DNA profiling or if enhancement methods interfere with DNA visualization.
• To optimize the sequential application of DD and enhancement techniques for effective latent DNA recovery.

Main Methods:

• Six standard latent fingerprint enhancement methods were tested: black powder, black magnetic powder, red magnetic powder, white powder, aluminum powder, and cyanoacrylate fuming.
• Fingerprint enhancement and DD staining were performed in both sequential orders (enhancement first, then staining; and staining first, then enhancement).
• Compatibility was assessed by evaluating DNA visualization, ridge pattern clarity, and the success of DNA amplification and profiling.

Main Results:

• DD effectively detected DNA with aluminum and white powders, and DD application did not hinder subsequent ridge pattern detection.
• Magnetic powders enhanced latent fingerprints post-DD staining, but latent DNA visualization was unsuccessful regardless of the order of application.
• Cyanoacrylate fuming did not adversely affect DD staining, though DNA amplification and profiling were unsuccessful in the presence of fluorescent artifacts.
• DD is compatible with aluminum and white powders, and cyanoacrylate fuming, with specific procedural considerations for magnetic powders.

Conclusions:

• Diamond™ Nucleic Acid Dye (DD) shows promise for latent DNA visualization, particularly with aluminum and white fingerprint powders.
• The sequence of application is critical when using DD with magnetic powders or cyanoacrylate fuming; DD should be applied first.
• Further research may be needed to overcome limitations with cyanoacrylate fuming and magnetic powders for simultaneous DNA and ridge pattern recovery.