Comparison of metal ions recovered during DNA analysis of brass ammunition and effects of copper and zinc ions on DNA profiling

Published:October 19, 2022DOI:


      Analyzing DNA from brass surfaces poses unique challenges that may result from DNA damage and/or PCR inhibition. To examine the relationship between the metal ions present in brass ammunition and the success of Short Tandem Repeat (STR) profiling, six recovery methods were tested to determine the identity and quantity of metal ions co-recovered during DNA sampling. In addition, DNA and metal ion solutions were created at varying concentrations to determine the threshold at which deleterious effects occur. The results of this study show that copper and zinc are recovered in the highest concentrations from both fired and unfired ammunition, but at substantially lower levels than previously published. Furthermore, most metal ions co-recovered with DNA were removed during DNA purification and complete STR profiles were generated when the concentrations of copper and zinc ions were less than 0.1 M and 0.03 M, respectively.


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        • Montpetit S.
        • O’Donnell P.
        An optimized procedure for obtaining DNA from fired and unfired ammunition.
        Forensic Sci. Int. Genet. 2015; 17: 70-74
        • Dieltjes P.
        • Mieremet R.
        • Zuniga S.
        • Kraaijenbrink T.
        • Pijpe J.
        • De Knijff P.
        A sensitive method to extract DNA from biological traces present on ammunition for the purpose of genetic profiling.
        Int. J. Leg. Med. 2011; 125: 597-602
        • Horsman-Hall K.M.
        • Orihuela Y.
        • Karczynski S.L.
        • Davis A.L.
        • Ban J.D.
        • Greenspoon S.A.
        Development of STR profiles from firearms and fired cartridge cases.
        Forensic Sci. Int. Genet. 2009; 3: 242-250
        • Elwick K.
        • Gauthier Q.
        • Rink S.
        • Cropper E.
        • Kavlick M.F.
        Recovery of DNA from fired and unfired cartridge casings: comparison of two DNA collection methods.
        Forensic Sci. Int. Genet. 2022; 102726
        • Polley D.
        • Mickiewicz P.
        • Vaughn M.
        • Miller T.
        • Warburton R.
        • Komonski D.
        • Kantautas C.
        • Reid B.
        • Frappier R.
        • Newman J.
        An investigation of DNA recovery from firearms and cartridge cases.
        Can. Soc. Forensic Sci. J. 2006; 39: 217-228
        • Prasad E.
        • Hitchcock C.
        • Raymond J.
        • Cole A.
        • Barash M.
        • Gunn P.
        • McNevin D.
        • van Oorschot R.A.
        DNA recovery from unfired and fired cartridge cases: a comparison of swabbing, tape lifting, vacuum filtration, and direct PCR.
        Forensic Sci. Int. 2020; 317110507
        • Thanakiatkrai P.
        • Rerkamnuaychoke B.
        Direct STR typing from fired and unfired bullet casings.
        Forensic Sci. Int. 2019; 301: 182-189
        • Holland M.M.
        • Bonds R.M.
        • Holland C.A.
        • McElhoe J.A.
        Recovery of mtDNA from unfired metallic ammunition components with an assessment of sequence profile quality and DNA damage through MPS analysis.
        Forensic Sci. Int. Genet. 2019; 39: 86-96
        • Kuffel A.
        • Gray A.
        • Daeid N.N.
        Impact of metal ions on PCR inhibition and RT-PCR efficiency.
        Int. J. Leg. Med. 2021; 135: 63-72
        • Jansson L.
        • Forsberg C.
        • Akel Y.
        • Dufva C.
        • Ansell C.
        • Ansell R.
        • Hedman J.
        Factors affecting DNA recovery from cartridge cases.
        Forensic Sci. Int. Genet. 2020; 48102343
        • Anastassopoulou J.
        Metal–DNA interactions.
        J. Mol. Struct. 2003; 651: 19-26
        • Govindaraju M.
        • Shekar H.
        • Sateesha S.
        • Raju P.V.
        • Rao K.S.
        • Rao K.
        • Rajamma A.
        Copper interactions with DNA of chromatin and its role in neurodegenerative disorders.
        J. Pharm. Anal. 2013; 3: 354-359
        • Bille T.W.
        • Fahrig G.
        • Weitz S.M.
        • Peiffer G.A.
        An improved process for the collection and DNA analysis of fired cartridge cases.
        Forensic Sci. Int. Genet. 2020; 46102238
        • Combs L.G.
        • Warren J.E.
        • Huynh V.
        • Castaneda J.
        • Golden T.D.
        • Roby R.K.
        The effects of metal ion PCR inhibitors on results obtained with the Quantifiler® Human DNA Quantification Kit.
        Forensic Sci. Int. Genet. 2015; 19: 180-189
        • Moreno L.I.
        • McCord B.R.
        Understanding metal inhibition: the effect of copper (Cu2+) on DNA containing samples.
        Forensic Chem. 2017; 4: 89-95