title: Exploring the recovery and detection of messenger RNA and DNA from enhanced fingermarks in blood.
abstract: Often in the examination of bloodstained fingermarks discussion occurs around whether to prioritise the fingerprint evidence or focus on the biological evidence. Collecting a sample for genetic profiling may result in the loss of ridge detail that could have been used for fingerprint comparison. Fingermark enhancement and recovery methods along with sample collection methods could also compromise downstream genetic analysis. Previous forensic casework has highlighted circumstances where, after enhancement had been performed, it would have been extremely valuable to both identify the body fluid and generate a DNA profile from the same sample. We enhanced depletion series of fingermarks made in blood, using single treatments consisting of aqueous amido black, methanol-based amido black, acid yellow and leucocrystal violet, and exposure to long wave UV light. We then extracted the DNA and RNA for profiling, to assess the recovery and detection of genetic material from the enhanced fingermarks. We have shown that genetic profiling of bloodstained fingermarks can be successful after chemical enhancement; however it may still be necessary to prioritise evidence types in certain circumstances. From our results it appears that even with visible bloodstained fingermarks, leucocrystal violet can reduce the effectiveness of subsequent messenger RNA profiling. Aqueous amido black and acid yellow also have adverse effects on messenger RNA profiling of depleted fingermarks with low levels of cellular material. These results help with forensic decision-making by expanding knowledge of the extent of the detrimental effects of blood-enhancement reagents on both DNA profiling and body fluid identification using messenger RNA profiling.
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Institute of Environmental Science and Research, Private Bag 92021, Auckland 1142, New Zealand.
authors.forename: A
authors.initials: A
authors.lastname: Fox
authors.affiliation: Auckland Fingerprint Section, New Zealand Police, Private Bag 92002, Auckland, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Gittos
authors.affiliation: Institute of Environmental Science and Research, Private Bag 92021, Auckland 1142, New Zealand.
authors.forename: S A
authors.initials: SA
authors.lastname: Harbison
authors.affiliation: Institute of Environmental Science and Research, Private Bag 92021, Auckland 1142, New Zealand.
authors.forename: R
authors.initials: R
authors.lastname: Fleming
authors.affiliation: Institute of Environmental Science and Research, Private Bag 92021, Auckland 1142, New Zealand. Electronic address: richard.wivell@esr.cri.nz.
authors.forename: R
authors.initials: R
authors.lastname: Wivell
mesh_terms: D004247:DNA / Q000097:blood*; D016172:DNA Fingerprinting; D003878:Dermatoglyphics; D005456:Fluorescent Dyes; D006801:Humans; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000097:blood*
chemical_list: D005456:Fluorescent Dyes; D012333:RNA, Messenger; D004247:DNA
keywords: Blood; DNA; Fingermark enhancement; Forensic science; Messenger RNA