By means of this ‘Frontiers in Genetics’ research topic, we are celebrating 30 years of the Comet Assay. The first paper on this single-cell gel electrophoresis assay was published in 1984 by O. Ostling and K.J. Johanson (Biochem. Biophys. Res. Commun. Vol.123: 291-298). The comet assay is a versatile and sensitive method for measuring single - and double-strand breaks in DNA. By including lesion-specific enzymes in the assay, its range and sensitivity are greatly increased, but it is important to bear in mind that their specificity is not absolute. The comet assay (with and without inclusion of lesion-specific enzymes) is widely used as a biomarker assay in human population studies - primarily to measure DNA damage, but increasingly also to assess the capacity of cells for DNA repair. Ostling and Johanson (Biochem. Biophys. Res. Commun., 1984) were also the first to report experiments to measure DNA repair, by simply following the decrease of DNA damage over time after challenging cells with ionising radiation. However, this approach is time-consuming and laborious as it requires an extended period of cell culture and is therefore not ideal for biomonitoring studies, which typically require high-throughput processing of many samples. As an alternative approach, the in vitro comet-based repair assay was developed: a cell extract is incubated with a DNA substrate containing specific lesions, and DNA incisions accumulate. The in vitro comet-based repair assay has been modified and improved over the past decade: it was first devised to measure base excision repair of oxidised purines in lymphocytes (Collins et al., Mutagenesis, 2001), but has since been adapted for other lesions and thus other repair pathways, as well as being applied to tissue samples in addition to cell suspensions. Even after 30 years, the comet assay is still in a growth phase, with many new users each year. Many questions are repeatedly raised, which may seem to have self-evident answers, but clearly, it is necessary to reiterate them for the benefit of the new audience, and sometimes being forced to think again about old topics can shed new light. Different applications of the comet assay are discussed in this special issue, including: genotoxicity testing in different organisms, human biomonitoring, DNA repair studies, environmental biomonitoring and clinical studies. Furthermore, we consider and where possible answer questions, including the ones raised by Raymond Tice at the 8th International Comet Assay Workshop in Perugia (Italy 2009): What is the spectrum of DNA damage detected by the various versions of the comet assay?; What are the limitations associated with each application?; What should be done to standardize the assay for biomonitoring studies?; Can the comet assay be used to monitor changes in global methylation status?; What cell types are suitable for detecting genotoxic substances and their effects in vivo and in vitro?; Can the assay be fully automated?; and more. So this ‘Frontiers in Genetics’ research topic is written for the beginner as well as for the experienced users of the comet assay.

This comprehensive, up-to-date text, which brings together the key practical elements of the rapidly evolving field of sperm DNA and chromatin abnormalities, is divided thematically into five main sections. Part I discusses human sperm chromatin structure and nuclear architecture, while part II presents laboratory evaluation of sperm DNA damage, including SCSA, SCD, TUNEL and Comet assays, and cytochemical tests. Biological and clinical factors in the etiology of sperm DNA damage are discussed in part III, including oxidative stress, abortive apoptosis, cancer, and environmental and lifestyle factors. Part IV presents clinical studies on the utility of sperm DNA damage tests, both with natural and ART-assisted pregnancies, and debates the clinical utility of such tests. Finally, part V discusses current treatment options, such as antioxidant therapy, varicocelectomy, advanced sperm processing techniques and the use of testicular sperm. We are now beginning to better understand the unique organization of the sperm chromatin, as well as the nature and etiology of sperm DNA damage. Written and edited by worldwide experts in andrology, A Clinician's Guide to Sperm DNA and Chromatin Damage is an excellent resource for reproductive medicine and REI specialists, urologists, reproductive biologists and any professional working with the infertile male.

This book, Environmental Health Risk - Hazardous Factors to Living Species, is intended to provide a set of practical discussions and relevant tools for making risky decisions that require actions to reduce environmental health risk against environmental factors that may adversely impact human health or ecological balances. We aimed to compile information from diverse sources into a single volume to give some real examples extending concepts of those hazardous factors to living species that may stimulate new research ideas and trends in the relevant fields.

Biomarkers in Toxicology, Second Edition, is a timely and comprehensive reference dedicated to all aspects of biomarkers that relate to chemical exposure and their effects on biological systems. This revised and completely updated edition includes both vertebrate and non-vertebrate species models for toxicological testing and the development of biomarkers. Divided into several key sections, this reference volume contains new chapters devoted to topics in microplastics, neuroimmunotoxicity and nutraceuticals, along with a look at the latest cutting-edge technologies used to detect biomarkers. Each chapter contains several references to current literature and important resources for further reading. Given this comprehensive treatment, this book is an essential reference for anyone interested in biomarkers across the scientific and biomedical fields. - Evaluates the expansive literature, providing one resource covering all aspects of toxicology biomarkers - Includes completely revised chapters, along with additional chapters on the newest developments in the field - Identifies and discusses the most sensitive, accurate, unique and validated biomarkers used as indicators of exposure - Covers special topics and applications of biomarkers, including chapters on molecular toxicology biomarkers, biomarker analysis for nanotoxicology, development of biomarkers for drug efficacy evaluation, and much more

Lung Cancer: New Insights for the Healthcare Professional: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Lung Cancer. The editors have built Lung Cancer: New Insights for the Healthcare Professional: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Lung Cancer in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Lung Cancer: New Insights for the Healthcare Professional: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

This book "New Insights into Toxicity and Drug Testing" covers all emerging technologies (profiling technologies, 3D cultures, next generation sequencing etc.), available methods and models to evaluate candidate drugs and medicinal plants with reference to toxicity, drug testing and development. This book is an original contribution of experts from different parts of the globe and the in-depth information will be a significant resource for scientists and physicians who are directly dealing with drugs / medicines and human life.

The in vivo alkaline single cell gel electrophoresis assay, also called alkaline Comet Assay is a method measuring DNA strand breaks in eukaryotic cells.