Rapid and low-cost strategy for detecting genome-editing induced deletion: A single-copy case

A quantitative method for aquaporin-1 protein using magnetic preconcentration and probe-based immunoassay coupling to inductively coupled plasma mass spectrometry in urine analysis

BACKGROUND

Aquaporin-1 (AQP1) protein plays a crucial role in intracellular and extracellular water homeostasis and fluid transport in organs and tissues associated with diverse life activities and is extremely abundant in the kidney. Accurate detection of AQP1 in urine can be applied as screening of early-stage disease. Application of magnetic preconcentration and probe-based signal amplification strategy coupling to inductively coupled plasma mass spectrometry (ICP-MS) is a more accurate, sensitive and specific detection method for AQP1 in complex biological samples compared to conventional methods.

RESULTS

We described an element-labelling strategy based on magnetic preconcentration and probe-based immunoassay coupling to ICP-MS detection. The magnetic beads (MBs) modified with epoxy groups were capable of enriching AQP1 proteins and separating them from complex matrices. The probe constructed by conjugating anti-AQP1 antibody molecules on the surface of gold nanoparticles could specifically recognize AQP1 proteins attached on MBs and be analyzed by ICP-MS. The concentration of AQP1 protein could be precisely quantified and amplified by 14,000 times through the corresponding signal of Au atoms. This assay for AQP1 protein quantification achieved a detection limit down to 0.023 ng mL-1, a broad linear calibration curve between 0.3 ng mL-1 and 30 ng mL-1, as well as outstanding specificity.

SIGNIFICANCE

The proposed method was successfully applied to detect AQP1 protein in human urine samples, showing the potential for its applications concerning accurate AQP1 quantification. It can also screen a wide range of proteins provided the antibodies specific to these target proteins are available.

Rapid visual genotyping method for germline mutants with small genomic fragment deletion by allele-specific PCR and lateral flow nucleic acid biosensor

BACKGROUND

Genome-editing techniques incorporating artificial nucleases develop rapidly and enable efficient and precise modification of genomic DNA of numerous organisms. The present research aimed to establish a rapid, sensitive and visual method for genotyping of germline genome-edited mutants with small genomic fragment deletion.

METHODS AND RESULTS

The genome-edited pigs with 2-bp deletion and 11-bp deletion of Myostatin (MSTN) gene generated by TALENs system were used as test materials to check the proposed allele-specific PCR (AS-PCR) and lateral flow nucleic acid biosensor (LFNAB) cascade method. AS-PCR can produce products with different tags to distinguish genome-edited alleles and wild-type alleles. A LFNAB was applied to do visual detection of AS-PCR products without using additional instruments. Furthermore, we demonstrated that AS-PCR and LFNAB cascade could accurately and visually distinguish genome-edited pigs with small genomic fragment deletion of Myostatin (MSTN) gene and wild-type pigs with limit of detection (LOD) of 0.1 ng.

CONCLUSION

The proposed AS-PCR and LFNAB cascade can do rapid and visual genotyping of genome-edited mutants with small genomic fragment deletion, serving as a platform for genome-edited animal genotyping.

A 'turn-on' ultra-sensitive multiplex real-time fluorescent quantitative biosensor mediated by a universal primer and probe for the detection of genetically modified organisms

Among the existing multiplex genetically modified organism (GMO) detection methods, significant problems are highlighted, including amplification asymmetry of different targets, and the low detection throughput, which limits their capacity to meet the requirements of high-throughput analysis. To mitigate these challenges, a 'turn-on' ultra-sensitive multiplex real-time fluorescent quantitative biosensor is developed. In this system, the multiplex ligation-dependent amplification (MLPA), universal primer and universal probe are innovatively combined, which can enhanced the amplification specificity, overcome asymmetric amplification and guarantee the homogeneity of amplification efficiency simultaneously. Furthermore, both single and multiplex detection results can be output by the fluorescent group labeled on universal TaqMan probes for different targets in real-time. After optimization, the quantitative detection limit was 5 pg. In conclusion, this strategy could serve as an important tool for GMO detection in processed and commercially available products, even in the fields that require reliable and sensitive detection of DNA targets.

Au@Pd Nanopopcorn and Aptamer Nanoflower Assisted Lateral Flow Strip for Thermal Detection of Exosomes

Conventional lateral flow biosensing technologies face the dual formidable challenges of poor sensitivity and cumbersome quantitative devices. Here, we developed a Au@Pd nanopopcorn and aptamer nanoflower assisted lateral flow strip (ANAN-LFS) with a thermal signal output to improve detection sensitivity. Moreover, a smartphone-based thermal reader was designed and meticulously optimized to hand-held style, realizing the essential portability of this quantitative device. Experimental studies revealed that the synthesized Au@Pd nanopopcorns clearly red-shifted into the near-infrared region, thus resulting in a higher photothermal response than the standard gold nanoparticles. Aptamer nanoflowers enhanced the system's biorecognition ability significantly compared with single-stranded aptamers due to their functional spatial structure, thus resulting in an even greater improvement in the sensitivity of the ANAN-LFS. With exosomes as model targets, the limit of detection (LOD) was calculated to be 1.4 × 10⁴ exosomes/μL, which exhibited a 71-fold improved analytical performance. The feasibility of this system for detecting spiked biological samples at clinical concentrations was also confirmed. These results suggest that the proposed strategy of integrating a ANAN-LFS with a smartphone-based thermal reader has great potential as a powerful tool for bioanalytical applications, offering the combined unique advantages of high sensitivity and expedient portability.