title: Detection of ultra-low levels of DNA changes by drinking water: epidemiologically important finding.
abstract: The safety of drinking water is essential to our health. In this context, the mutagenicity of water needs to be checked strictly. However, from the methodological limit, the lower concentration (less than parts per million) of mutagenicity could not be detected, though there have been of interest in the effect of less concentration mutagens. Here, we describe a highly sensitive mutation assay that detects mutagens at the ppb level, termed genome profiling-based mutation assay (GPMA). This consists of two steps; (i) Escherichia coli culture in the medium with/without mutagens and (ii) Genome profiling (GP) method (an integrated method of random PCR, temperature gradient gel electrophoresis and computer-aided normalization). Owing to high sensitivity of this method, very low concentration of mutagens in tap water could be directly detected without introducing burdensome concentration processes, enabling rapid measurement of low concentration samples. Less expectedly, all of the tap waters tested (22 samples) were shown to be significantly mutagenic while mineral waters were not. Resultantly, this article informs two facts that the GPMA method is competent to measure the mutagenicity of waters directly and the experimental results supported the former reports that the city tap waters contain very low level of mutagenicity reagent trihalomethanes.
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan koichi@fms.saitama-u.ac.jp.
authors.forename: Parmila
authors.initials: P
authors.lastname: Kumari
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan koichi@fms.saitama-u.ac.jp.
authors.forename: Meiko
authors.initials: M
authors.lastname: Kamiseki
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan.
authors.forename: Manish
authors.initials: M
authors.lastname: Biyani
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Nemoto
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan.
authors.forename: Takuyo
authors.initials: T
authors.lastname: Aita
authors.affiliation: Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama 338-8570, Japan and Department of Bioengineering, University of Tokyo 2-11-16, Yayoi, Bunkyo-Ku, Tokyo 113-8656, Japan koichi@fms.saitama-u.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nishigaki
mesh_terms: D004247:DNA / Q000187:drug effects; D004252:DNA Mutational Analysis; D060766:Drinking Water; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D009153:Mutagens / Q000633:toxicity*
chemical_list: D060766:Drinking Water; D009153:Mutagens; D004247:DNA
keywords: GPMA; drinking water; high sensitivity; mutagens; mutation assay