Genetic Engineering & Biotechnology News

AUG 2017

Genetic Engineering & Biotechnology News (GEN) is the world's most widely read biotech publication. It provides the R&D community with critical information on the tools, technologies, and trends that drive the biotech industry.

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Genetic Engineering & Biotechnology News | GENengnews.com | AUGUST 2017 | 25 (CODIS), which analyzes STRs at 13 specific loci and several additional loci to determine human cell-line authenticity. Commercial kits for STR profiling are available, but conclusive identification can be ensured by using a repository such as the one maintained by the ECACC or a core facility that specializes in this type of analysis. No standardized method yet exists to validate the identity of nonhuman cell lines; however, ATCC is currently working with the Na- tional Institute of Standards and Technology (NIST) on an authentication method using NIST-identified STR markers. DNA Barcoding DNA barcoding involves PCR amplifica- tion and DNA sequencing of specific regions of mitochondrial DNA. The cytochrome c oxidase subunit 1 mitochondrial region (COI) is the standard target for humans; the rbcL re- gion is the standard target for plants. In these regions, the DNA sequence is the "barcode" that differentiates species, although some variation exists between individuals of the same species. Storage and Handling The proper storage and handling of cells and cell culture reagents, as well as good asep- tic cell culture technique, can minimize con- tamination and thus improve the reproduc- ibility of experimental data. Storage Best Practices • Create a reserve of cells at earlier passages to serve as a cell bank. • Purchase media, sera, and other culture reagents that are endotoxin-free and manufactured under cGMP. Sera should be tested for mycoplasma and viruses. • Each researcher should maintain a personal stock of reagents, if possible, to reduce bacterial and cross- contamination. • Maintain a separate bottle of media for each cell line. • Purchase fresh, validated cells only. Do not accept cells from other laboratories. The most common source of mycoplasma infection in cell culture research is a previously infected culture. • Maintain a log of mycoplasma and valida- tion testing. Retain CofAs for reference. • Cell lines should be stored below the glass point of water (at least −150 °C). Monitor nitrogen storage temperature and maintain a temperature log. Program an alert to sound if the temperature exceeds a certain deviation from the set temperature. Handling Best Practices • Avoid distractions to prevent cross- contamination when working with cells. • Use antibiotic-free media unless undertaking primary culture. Overuse of antibiotics can lead to resistant bacterial strains. • Take care when using two or more antibiotics in the same culture, as the cytotoxic concentrations for the combined treatments are lower than those listed for the individual antibiotics. • Discard waste and spray hood with 70% ethanol after use. When multiple cell lines are in use, work with one cell line at a time and clean the hood before moving to the next cell line. • Do not allow cells to become fully confluent. Passage cells at 70–80% confluency or as advised by an ECACC or a ATCC data sheet. • Do not use incoming cell lines until testing has confirmed the absence of mycoplasma and the identity of the line. • Document new cell-line details upon acquisition. Record how many times a cell line has been passaged, as some cell lines exhibit different characteristics after multiple passages. Implement a standard for when to discard cells in culture and thaw a vial of stock. Summary Cell-line contamination poses a serious threat to the integrity of biomedical research. Following best practices for the validation, storage, and handling of cell culture can help to address this ongoing challenge and there- by improve the reliability of experimental research data. References available online View It Now! On Demand DURATION 60 minutes COST Complimentary Speakers Decoding Transcriptional Regulation by Genome-Wide Reporter Assays and Large-Scale Transfection Despite our knowledge of the complete genome sequences of several dozen species and high-quality annotation of the protein coding genes, the identification of active regulatory elements remains challenging, especially for distal enhancers. Traditional methods to measure enhancer activity directly are limited by throughput, so conventional approaches depend largely on indirect methods that profile features correlated with regulatory elements including the chromatin landscape and transcription factor binding sites. In this GEN webinar, we will learn about two novel reporter assays, STARR-seq and STAP-seq, ectopic, plasmid-based, massively parallel reporter assays that can directly and quantitatively measure the activity of millions of candidate sequences for enhancers and core promoters. Moreover, we will learn how these reporter assays were enabled by MaxCyte's scalable flow electroporation technology to attain high transfection efficiencies of plasmid reporter libraries—key to the reporter assays' success. A live Q&A session will follow the presentations, offering you a chance to pose questions to our expert panelists. Who Should Attend • Gene expression researchers • Scientists interested in large-scale transfection • Molecular biologists • Transcriptomic scientists • Genomics and epigenetic researchers Free Registration! www.GENengnews.com/transfection Webinars You Will Learn • How high-throughput transcriptional reporter assays coupled to large-scale transfection of cultured cells, enables the study of transcriptional regulation on a genome-wide scale • About the STARR-seq and STAP-seq methods, two technologies developed to study genome-wide enhancer and core promoter activity • About new results obtained by applying these methods to different questions in gene regulation in the Drosophila S2 cell model INTRODUCTION BY: Peer Heine, Ph.D. Field Application Scientist, Europe MaxCyte Vanja Haberle, Ph.D. Postdoctoral Researcher Research Institute of Molecular Pathology Vienna Cosmas Arnold, Ph.D. Research Associate Research Institute of Molecular Pathology Vienna Produced with support from Bioprocessing Patrick Schneider, Ph.D., is head of R&D, and business development, MilliporeSigma. Website: www.emdmillipore.com. Tutorial

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