Comparison of PCR Kits for Forensic Analysis of Plant

Recently, plant DNA has been utilized to discriminate or identify forensic botanical samples. In a forensic examination of a plant, various species and plant parts are considered as evidence. PCR amplification has sometimes failed because the samples contain some PCR inhibitors. In this study, to increase the success rate of PCR amplification of plant materials, four kinds of commercially available PCR kits, which showed resistance to PCR inhibitors, were evaluated by two experiments. One experiment was PCR amplification with the addition of chemicals to PCR solution; the other one was PCR amplification using non-purified DNA extracted from plants. The concentrations of chemicals, which inhibited PCR amplification, were different between four kits. Humic acid showed a high inhibitory power, and the concentration of it inhibiting PCR amplification was smaller than the other chemicals by one or two orders of magnitude. PCR amplification from non-purified DNA was succeeded by using a PCR kit, but there was no kit that enabled us to amplify all plant samples. Two kits could amplify more plant samples than the other kits and previous methods. The results indicate that these two PCR kits, which are designed for PCR of plant-derived DNA, are more suitable for forensic examinations of plants.