Genetic Engineering & Biotechnology News

MAY15 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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See Novel on page PB Genetic Engineering & Biotechnology News | GENengnews.com | MAY 15, 2017 | 9 The Journal of Molecular Diagnostics. Ad- mittedly, collection of hard-to-find real clini- cal specimens can be challenging and costly. Nevertheless, it's important, and some of the analytical verification studies for a biomarker assay should be done with the "real" clinical specimen that the assay is intended to be used with, asserted Dr. Wu. For example, genomic DNA isolated from cell lines versus tumor tissues versus a patient's blood will all be different. "Analyti- cal validation can't just be done with cell line DNA," cautioned Dr. Wu. "It's too clean, and it doesn't give you the variability found in sample specimens." It's challenging to determine the ground truth when using clinical specimens. "You might say your assay device can measure cer- tain copy numbers of DNA, but you need to verify your claim with an independent meth- od," advised Dr. Wu. "Typically, we develop more than one method to measure the same biomarker." The biomarker is measured not only in the assay intended for the customer, but also in independent tests on the same clinical specimens. "I don't see that being done with too many others in the industry as a standard practice," she concluded. VIAFLO II VIAFLO II VOYAGER II VOYAGER II ASSIST ASSIST VIAFLO 96 I 384 Electronic hand held pipette Easy 96 and 384 channel pipetting and increased productivity due to a full range of pipetting modes including repeat dispense, serial dilute and customized programs. Interchangeable pipetting heads allow precise pipetting between 0.5 and 1250 ┬Ál. MULTIWELL PLATE PIPETTING EASY AND AFFORDABLE www.integra-biosciences.com EVOLVE EVOLVE Visit us at ASM 2017 Booth #1337, June 2 - 4 New Orleans, LA Drug Discovery See Biomarker Validation on page 10 Multiplex immunoassays are powerful tools for biomarker screening and discovery, and take a high level of expertise to develop and produce consistently. Three key aspects of multiplex immunoassay development include selecting biologically relevant targets and high-quality antibody pairs, constructing calibration curves for quality control, and optimizing reagents to reduce plex-level effects and cross-reactivity between assays. Specifically, screening for the right antigens and anti- bodies from the beginning significantly affects all other downstream steps. Variability in the raw materials used for these processes must be carefully tracked to reduce any subsequent impact on the finished panel, and robust multiplex assay development should employ strategies to control intra-lot variation by sourcing raw materials from the same lot whenever possible. If there is a need to dip into a fresh batch or lot, it is important to follow up with additional validation steps. The new batch/lot of raw materials should be tested for concentration and activity in order to maintain consis- tent final assay performance. Furthermore, the final assay should be validated as a whole to ensure uniformity be- tween lots. For example, Bio-Rad Bio-Plex multiplex immunoassays are typically validated at the raw material and finished kit levels to ensure accurate, dependable, and reproducible performance on biological samples, according to Bio-Rad officials. Capture and detection antibody selection is also crucial to overall assay performance. Antibodies validated for single-plex ELISAs likely won't perform similarly in multiplex assay applications and Western blotting anti- bodies may not be suitable in a multiplex assay either. Thus, diligent qualification and validation of antibody pairs must be carried out on the same platform used for the final assay to ensure optimum performance. Choosing an assay with validated, fit-for-purpose antibodies that has been carefully tested for quality will generate consistently accurate results. n Biomarker Discovery Assays Bio-Rad's Bio-Plex 200 system offers researchers a multiplex assay solution that is designed to permit analysis of up to 100 biomolecules in a single sample.

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