Bryce S.M.,Litron Laboratories, Ltd. |
Shi J.,BioReliance |
Nicolette J.,Abbott Laboratories |
Diehl M.,Abbott Laboratories |
And 5 more authors.
Environmental and Molecular Mutagenesis | Year: 2010
A flow cytometric method for analyzing suspension cell cultures for micronucleus content has been previously reported (Avlasevich et al. : Environ Mol Mutagen 47: 56-66). The experiments described herein were undertaken to evaluate the compatibility of this method (In Vitro MicroFlow®) with attachment cells. Initially, CHO-K1 cells were studied in nine independent experiments using mitomycin C and cyclophosphamide. The results demonstrated the effectiveness of the cell processing procedure, and also provided historical control data that were useful for setting criteria for making positive calls. Subsequently, CHO-K1 cells were treated with methyl methanesulfonate, mitomycin C, etoposide, vinblastine sulfate, dexamethasone, and sodium chloride. Whereas the four genotoxicants were each observed to increase micronucleus frequencies, the nongenotoxicants induced no such response up to cytotoxic concentrations. Following this initial work, inter-laboratory transferability was evaluated across three sites using a common cell staining and analysis protocol for CHO-K1 or V79 cells that had been treated with the ten chemicals listed in Annex 3 of the OECD Draft Proposal for a New Guideline 487: In Vitro Mammalian Cell Micronucleus Test. With the exception of benzo[a]pyrene at one site, each laboratory observed increased micronucleus frequencies for the genotoxicants, whereas no significant induction occurred with the non-genotoxicants. Interestingly, the method appeared to distinguish between genotoxic modes of action, as only aneugens increased the average micronucleus fluorescence intensity and the frequency of hypodiploid nuclei. Collectively, these data suggest that flow cytometry is capable of providing reliable micronucleus counts, and that additional information is obtained that appears to discern genotoxic modes of action. © 2009 Wiley-Liss, Inc. Source
Bohnenberger S.,Harlan Cytotest Cell Research Harlan CCR GmbH |
Bruce S.W.,BioReliance |
Kunkelmann T.,Harlan Cytotest Cell Research Harlan CCR GmbH |
Pant K.,BioReliance |
And 4 more authors.
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2012
This catalogue is a display of Syrian hamster embryo (SHE) cell colony photos representative of the cell transformation assay (CTA) carried out at pH 6.7. It is intended as a visual aid for the identification and the scoring of cell colonies in the conduct of the assay.A proper training from experienced personnel together with the protocol reported in this issue and the present photo catalogue will support method transfer and consistency in the assay results. © 2011 Elsevier B.V. Source
Onions D.,BioReliance |
Biologicals | Year: 2010
There has been an upsurge of interest in developing new veterinary and human vaccines and, in turn, this has involved the development of new mammalian and insect cell substrates. Excluding adventitious agents from these cells can be problematic, particularly for cells derived from species with limited virological investigation. Massively parallel sequencing is a powerful new method for the identification of viruses and other adventitious agents, without prior knowledge of the nature of the agent. We have developed methods using random priming to detect viruses in the supernatants from cell substrates or in virus seed stocks. Using these methods we have recently discovered a new parvovirus in bovine serum. When applied to sequencing the transcriptome, massively parallel sequencing can reveal latent or silent infections. Enormous amounts of data are developed in this process usually between 100 and 400. Mbp. Consequently, sophisticated bioinformatic algorithms are required to analyse and verify virus targets. © 2010. Source
Harper M.S.,DuPont Pioneer |
Amanda Shen Z.,DuPont Company |
Barnett J.F.,Charles River Laboratories Preclinical Services |
Krsmanovic L.,BioReliance |
And 2 more authors.
Food and Chemical Toxicology | Year: 2010
N-acetylglycine (NAGly) has been identified as a minor constituent of numerous foods. The current paper reports the outcome of in vitro and in vivo genotoxicity, acute oral and repeated dose dietary toxicology studies conducted with NAGly. No evidence of genotoxicity was observed with NAGly in vitro bacterial tester strains or in vivo bone marrow micronucleus studies conducted in mice. No mortalities or evidence of adverse effects were observed in Sprague-Dawley rats following acute oral gavage with NAGly at a dose of 2000. mg/kg of body weight or following repeated dose dietary exposure to NAGly at targeted doses of 100, 500, or 1000. mg/kg of body weight/day for 28. days. No biologically significant or test substance related differences were observed in body weights, feed consumption, or clinical pathology response variables in any of the treatment groups. Based on these results it was concluded that NAGly is not genotoxic or acutely toxic. Further, the no-observed adverse-effect-level (NOAEL) for systemic toxicity from repeated dose dietary exposure to NAGly was 898.9. mg/kg of body weight/day for male rats and 989.9. mg/kg of body weight/day for female rats. © 2010 Elsevier Ltd. Source
News Article | September 9, 2016
MilliporeSigma launched a first-of-its-kind gene editing technology to modify CHO cell lines to be resistant to minute virus of mice (MVM), a common contamination threat that remains despite the shift to chemically-defined, animal component-free manufacturing processes. CHO cells are commonly used in the manufacture of biologics. The new Centinel technology targets genes which play a role in MVM susceptibility. Viral contaminations like MVM can have major consequences for biopharmaceutical manufacturers, costing hundreds of millions of dollars, according to industry reports. The greatest impact of such contamination is on patients, as access to therapies can be put in jeopardy. The technology provides manufacturers with an additional path for mitigating the risk of MVM contamination, while maintaining an equivalent level of protein quality and cell line productivity. Under the program, the company can modify customers’ CHO cell lines to provide viral resistance to MVM. A patent application has been submitted for the technology used in the gene editing approach to viral resistance. The company’s BioReliance testing services can validate MVM resistance and demonstrate the virus is not propagated in the cell line. Alternatively, customers can purchased the zinc finger nuclease pairs to engineer cell lines directly. The technology builds on the company’s expertise in gene editing and biomanufacturing processes, as well as its in-depth understanding of the regulatory environment. In addition to enhancing the safety of biomanufacturing, MilliporeSigma is also applying this expertise and approach to develop other technologies and services, including those supporting the cell therapy industry.