Date of Award
Master of Science (MS)
First Advisor or Mentor
Nicholas D.K. Petraco
Recovery of trace DNA is important in forensic casework because it is the main type of biological evidence found in both violent and non-violent crimes. Researchers have been trying to determine if there are individual differences in shedding propensity, or how much DNA an individual leaves behind. A model for determining this would benefit evidence interpretation if passive transfer scenarios are being considered, as it can affect the probative value of DNA evidence. This study compared the amount of DNA collected with adhesive D-Squame tape disks from the fingers of individual’s washed non-dominant and dominant hands after 30 minutes of no activity and 60 minutes with controlled activity, with the goal to correlate DNA yield to other biological characteristics. Two samples were taken from each hand of 22 volunteers and extracted using QIAamp DNA Investigator chemistry (QIAGEN, Germantown, MD). Quantification was performed using Quantifiler Trio (ThermoFisher Scientific, Waltham, MA). Dominant hand samples (60 minutes with activity) showed a higher average DNA concentration than non-dominant hands (30 minutes no activity), however this difference was not significant. The 22 participants provided skin surface measurements for hydration, sebum, and melanin content, and questionnaire responses covering other biological factors. The amount of DNA recovered did not correlate to melanin content, skin hydration, sebum production, and BMI. There was some correlation between DNA concentration and skin-self touch counts, age, time since last shower, or self-declared sweating characteristics. A larger sample population will be collected to further analyze the possible correlation between sebum content, hydration, and shedding propensity.
Cedillo-Cruz, Ines G., "Biological Factors Affecting DNA Shedding Propensity" (2022). CUNY Academic Works.