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Conventional magnetic solid-phase extraction materials for DNA typically require multistep synthesis to coat functional layers onto an iron oxide core, which complicates their preparation and limits practical application.

In this study (USD$39.95 purchase required) the authors developed a magnetic ionic liquid-functionalized graphene adsorbent (G-MIL) that integrates the magnetic component and the functional modifier into a single material, thereby eliminating the need for a separate magnetic core and simplifying the synthesis process. This G-MIL material enabled the development of a rapid, one-step DNA extraction method that combines vortex-assisted dispersion and magnetic separation, effectively integrating isolation, enrichment, and purification without tedious centrifugation steps.

They optimised the method and applied it to the authentication of beef products.  They report good selectivity for bovine DNA in the presence of interfering proteins and amino acids. They report that their approach was successfully applied to the authentication of beef products, reliably distinguishing pure beef from adulterated counterparts.

Photo by Sangharsh Lohakare on Unsplash

Mixed-milk cheeses (cheese made with a mix of milk from different species) are common on the European market, particularly in Spain.  They present a motive to fraudulently increasing the proportion of the cheapest milk species above its maximum legal specification.  For example, Iberico cheese must contain a maximum of 50% cow's milk and a minimum of 15% each of goat's and sheep's milk. Verifying the proportions of milk in the final product by quantitative analytical testing is a challenge.

In this study (open access) the authors developed and validated a quantitative LC-MSMS method based on protein markers for each species.  They selected their markers using shotgun proteomics of 6 cheeses of known proportions that had been specially made in a pilot plant following the industrial process for manufacturing Iberico-type cheese.

They optimised a quantitative low-resolution LC-MSMS method for these markers and then validated it following AOAC guidelines.  They report that the method demonstrated linearity with detection limits less than 1% for all 3 species and showed good repeatability (CV = 8%), reproducibility (CV = 10%) and accuracy (99.6%),.

They applied the method commercial cheeses with diverse compositions and ripening times. They report that measurements were unaffected by either ripening or production process.

Photo by Sam Carter on Unsplash