Structure-Selective Differentiation of Deletion Mutation in Circulating Tumor DNA by Dual Probe-Based Isothermal Amplification

A rapid dual probe-based fluorimetric assay was developed to detect deletion mutation in circulating tumor DNA, through structure-selective isothermal amplification and pattern recognition. This method can detect both homozygous and...

Miniaturized Fluorimetric Method for Quantification of Zinc in Dry Dog Food

Zinc is an essential trace element for animals in several biological processes, particularly in energy production, and it is acquired from food ingestion. In this context, a microplate-based fluorimetric assay was developed for simple, fast, and low-cost determination of zinc in pet food using 2,2′-((4-(2,7-difluoro-3,6-dihydroxy-4aH-xanthen-9-yl)-3-methoxyphenyl)azanediyl)diacetic acid (FluoZin-1) as fluorescent probe. Several aspects were studied, namely, the stability of the fluorescent product over time, the FluoZin-1 concentration, and the pH of reaction media. The developed methodology provided a limit of detection of 1 μg L−1 in sample acid digests, with a working range of 10 to 200 μg L−1, corresponding to 100–2000 mg of Zn per kg of dry dog food samples. Intraday repeatability and interday repeatability were assessed, with relative standard deviation values < 3.4% (100 μg L−1) and <11.7% (10 μg L−1). Sample analysis indicated that the proposed fluorimetric assay provided results consistent with ICP-MS analysis. These results demonstrated that the developed assay can be used for rapid determination of zinc in dry dog food.

A new approach based on isoindole formation reaction for sensitive fluorimetric assay of milnacipran in tablets and biological fluids (plasma/urine)

The current study describes a new, sensitive, and economic protocol for milnacipran analysis.