This study (open access) builds upon previously published work. The authors expand the scope of multiplex digitalPCR (dPCR) analysis for undeclared GM soy to simultaneously check for 19 different GM events and the lectin (Le1) endogene, and proved the method’s transferability to a popular commercial dPCR platform.
They used a nanowell plate-based all-in-one dPCR system, the QIAGEN QIAcuity One. The method used four 5-plex assays, taking advantage of the platform’s multiple fluorescence detection channels. DNA was extracted by the cetyltrimethylammonium bromide (CTAB) method, with RNase-A and proteinase-K for removal of RNA and protein, respectively, as described in Annex A.3 of ISO21571:2005. Quantification by simplex and multiplex assays was compared by testing CRM solutions containing single GM events. The authors report that all four 5-plex assays showed results comparable with simplex assays
They report that the methods complied with the minimum performance requirements in terms of specificity, trueness, precision, sensitivity and dynamic range, making them suitable for use in routine detection and quantification of GM crops.
They conclude that approach represents a significant step forward by providing discriminative quantification of a large number of targets. The use of a commercial system prooves that quantitative multiplexing can become time and cost-effective, and they believe that their approach is particularly well suited to regulatory compliance testing. Sample compartmentalization, temperature cycling, and fluorescence detection are all performed automatically on the same machine, greatly simplifying the workflow and minimizing hands-on time. The experimental protocol requires no specialized sample handling, allowing it to be performed by operators familiar with qPCR workflow without additional training.
Photo by Meredith Petrick on Unsplash
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