Visualizing Cellular Material on Touched Surfaces

Authors: Briana Hojo BS , Alena Monarca BS and Heather Miller Coyle*

DOI: 10.23880/ijfsc-16000446

Volume 10, Issue 2

Abstract

Touch deposits are comprised of oils, proteins, free-DNA molecules, nucleated cells, and cells undergoing programmed cell death. Previous studies have researched the use of fluorescent nuclear staining dyes, such as Diamond™ Nucleic Acid Dye (DD), to visualize DNA on an object, but not many studies have been conducted using other dyes, such as Nuclear Fast Red (NFR) and Trypan Blue (TB), on porous and non-porous substrates in comparison. The purpose of this research was to investigate and compare the effectiveness of the chemical enhancement reagents Diamond™ Nucleic Acid Dye, Nuclear Fast Red, and Trypan Blue for the visualization of DNA and cells. This research study shows that Diamond™ Nucleic Acid Dye and Nuclear Fast Red are effective at visualizing DNA on simulated forensic evidence. Trypan Blue was effective at visualizing apoptotic or necrotic cells with disrupted membranes. All three staining methods could be performed easily and are useful tools for forensic examiners to better understand the nature of the cellular material left behind after a single touch to the surface. Diamond™ Nucleic Acid Dye worked best on nonporous dark or clear surfaces while Nuclear Fast Red and Trypan Blue dyes worked well on all surfaces with high contrast-colors.

Keywords: Trace DNA; Cell Biology; Diamond Dye; Nuclear Fast Red; Trypan Blue

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