Droplet digital PCR versus real-time PCR for in-house validation of porcine detection and quantification protocol: An artificial recombinant plasmid approach

A temperature compensated fiber probe for highly sensitive detection in virus gene biosensing

This research presents an innovative reflective fiber optic probe structure, mutinously designed to detect H7N9 avian influenza virus gene precisely. This innovative structure skillfully combines multimode fiber (MMF) with a thin-diameter seven-core photonic crystal fiber (SCF-PCF), forming a semi-open Fabry-Pérot (FPI) cavity. This structure has demonstrated exceptional sensitivity in light intensity-refractive index (RI) response through rigorous theoretical and experimental validation. The development of a quasi-distributed parallel sensor array, which provides temperature compensation during measurements, has achieved a remarkable RI response sensitivity of up to 532.7 dB/RIU. The probe-type fiber optic sensitive unit, expertly functionalized with streptavidin, offers high specificity in detecting H7N9 avian influenza virus gene, with an impressively low detection limit of 10-2 pM. The development of this biosensor marks a significant development in biological detection, offering a practical engineering solution for achieving high sensitivity and specificity in light-intensity-modulated biosensing. Its potential for wide-ranging applications in various fields is now well-established.

Nanoplate-based digital PCR for highly sensitive pork DNA detection targeting multi-copy nuclear and mitochondrial genes

The inclusion of ingredients derived from pigs in highly processed consumer products poses a significant challenge for DNA-targeted analytical enforcement, which could be overcome by using digital PCR. However, most species detection methods use digital PCR to target single-copy nuclear genes, which limits their sensitivity. In this work, we examined the performance of a nanoplate-based digital PCR method that targets multi-copy nuclear (MPRE42) and mitochondrial (Cytb) genes. Poor separation of positive and negative partitions, as well as a 'rain effect' were obtained in the porcine-specific MPRE42 assay. Among the optimization strategies examined, the inclusion of restriction enzymes slightly improved the separation of positive and negative partitions, but a more extensive 'rain effect' was observed. The high copy number of the MPRE42 amplicon is hypothesized to contribute to the saturation of the positive signal. In contrast, the porcine-specific Cytb assay achieved perfect separation of positive and negative partitions with no 'rain effect'. This assay can detect as little as 0.4 pg of pork DNA, with a sensitivity of 0.05% (w/w) in a pork-chicken mixture, proving its applicability for detecting pork in meat and meat-based products. For the MPRE42 assay, potential applications in highly degraded products such as gelatin and lard are anticipated.