Presently, clopidogrel is the standard therapeutic drugs for antiplatelet therapy. Variants in the CYP2C19 gene influence the clinical response of clopidogrel. Thus, the US Food and Drug Administration suggested CYP2C19 genotyping needs to identify before taking medicine. Due to high cost, time consuming, and sophisticated instruments, current single nucleotide polymorphism detection methods are limited in clinical application. In the present study, we established a genotyping method for CYP2C19, which combines amplification refractory mutation system (ARMS)-PCR with a lateral flow assay used gold magnetic nanoparticles (GMNPs) named as PCR-gold magnetic lateral flow assay system (PCR-GoldMag LFA). The PCR products with specific genotype can be explained within 5 minutes, either through visual or by a magnetic reader automatically according to the captured GMNPs probes on the test lines of the LFA strips. The limit of detection of this method is 5 ng of genomic DNA. The PCR-GoldMag LFA system was applied in a clinical trial with 1356 samples of Han Chinese. The concordance rate between the LFA system and sequencing is 99.93%. The allele frequency of CYP2C19*2 and CYP2C19*3 are 30.38 and 7.08% in Han Chinese, respectively. This method provides a new way in the clinical application of CYP2C19 genotyping to guide the clopidogrel medication.
With the increasing global threat of various diseases and infections, it is essential to develop a fast, low-cost, and easy-to-use point-of-care testing (POCT) system for inspections at all levels of medical institutions and self-examination at home. In this work, gold magnetic nanoparticles (GMNPs) are used as the key material, and a rapid visual detection method is designed through integrating loop-mediated isothermal amplification (LAMP) and lateral flow assay (LFA) biosensor for detecting a variety of analytes which includes whole blood, buccal swabs, and DNA. It is worth to note that the proposed method does not need DNA extraction. Furthermore, uracil DNA glycosylase (UDG) is employed to eliminate carrier contamination for preventing false positive results. The whole detection process can be finished within 25 min. The accuracy of detection is measured by assessing the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) C677T. The detection limit of the newly developed extraction-free detection system for MTHFR C677T is 0.16 ng/μL. A preliminary clinical study of the proposed method is carried out by analyzing 600 clinical samples (including 200 whole blood samples, 100 buccal swabs, and 300 genomic DNA samples). The results indicate that the proposed method is 100% consistent with the sequencing results which provides a new choice for POCT and shows a broad application prospect in all levels of medical clinics and at home.
Seasonal and persistent outbreaks of influenza viruses represent a significant challenge to global public health. Rapid, convenient and accurate diagnosis methods of influenza viruses are crucial for timely treatment to mitigate morbidity and mortality during both seasonal epidemics and pandemics. However, current diagnostic tools often face limitations in speed, accuracy or complexity of result interpretation; there is a great need for more efficient detection technology for influenza virus, especially for use in resource‐limited settings or during large‐scale outbreaks. This study developed a dual ‘RT‐LAMP‐LFA’ detection technology with gold magnetic nanoparticles for influenza virus. This method can simultaneously detect influenza A and B genes as well as internal reference genes within 35 min, with a detection limit of 80 copies/mL. This is the first time the RNase P gene has been introduced into a gold magnetic nanoparticle lateral flow assay system as a quality control measure to monitor the entire sampling and amplification process in virus detection and reveals the effects of loop primer deficiencies on the stability of the dual ‘RT‐LAMP‐LFA’ detection technology. Using fluorescent PCR detection technology as a benchmark, the analysis of a total of 70 clinical samples demonstrated a 100% agreement rate, confirming the applicability and accuracy of the dual ‘RT‐LAMP‐LFA’ detection system. This dual ‘RT‐LAMP‐LFA’ detection technology offers a novel option for diagnostic technology in hierarchical medical testing, presenting significant social importance and broad application prospects.
Background: Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. The wide distribution and multifunctional properties of ACE suggest it’s involvement in various pathophysiological conditions. Results: In this study, a novel visual detection method for ACE I/D polymorphisms was designed by integrating direct PCR without the need for DNA extraction using gold magnetic nanoparticles (GMNPs)-based lateral flow assay (LFA) biosensor. The entire detection procedure could enable the genotyping of clinical samples in about 80 min. The detection limit was 0.75 ng and results could be obtained in 5 min using the LFA device. Three hundred peripheral blood samples were analyzed using the direct PCR-LFA system and then verified by sequencing to determine accuracy and repeatability. A clinical preliminary study was then performed to analyze a total of 633 clinical samples. Conclusions: After grouping based on age, we found a significant difference between the genotypes and the age of patients in the CHD group. The introduction of this method into clinical practice may be helpful for the diagnosis of diseases caused by large fragment gene insertions/deletions.