Fast infectious diseases diagnostics based on microfluidic biochip system

Abstract

Molecular diagnostics is one of the most important tools currently in use for clinical pathogen detection due to its high sensitivity, speci¯city, and low consume of sample and reagent is keyword to low cost molecular diagnostics. In this paper, a sensitive DNA isothermal ampli¯-cation method for fast clinical infectious diseases diagnostics at aM concentrations of DNA was developed using a polycarbonate (PC) micro°uidic chip. A portable confocal optical°uo-rescence detector was speci¯cally developed for the micro°uidic chip that was capable of highly sensitive real-time detection of ampli¯ed products for sequence-speci¯c molecular identi¯cation near the optical di®raction limit with low background. The molecular diagnostics of Listeria monocytogenes with nucleic acid extracted from stool samples was performed at a minimum DNA template concentration of 3.65 aM, and a detection limit of less than¯ve copies of genomic DNA. Contrast to the general polymerase chain reaction (PCR) at eppendorf (EP) tube, the detection time in our developed method was reduced from 1.5 h to 45 min for multi-target parallel detection, the consume of sample and reagent was dropped from 25 L to 1.45 L. This novel micro°uidic chip system and method can be used to develop a micro total analysis system as a clinically relevant pathogen molecular diagnostics method via the ampli¯cation of targets, with potential applications in biotechnology, medicine, and clinical molecular diagnostics.

Smartphone-Based Droplet Digital LAMP Device with Rapid Nucleic Acid Isolation for Highly Sensitive Point-of-Care Detection

“…These devices usually obtain detection results by means of real-time fluorescence PCR detection. Several studies have managed to reduce the size, price, and complexity of these systems by means of isothermal amplification. , Some studies have also used end point detection methods, such as nucleic acid lateral flow, to miniaturize the instrument. , In recent years, some studies have realized electrochemical detection, colorimetric, fluorescent, and surface plasmon resonance detection of samples by taking photos using smart phone, which further improves the mobility of the nucleic acid POCT device. , However, most of these POCT devices are based on traditional nucleic acid amplification methods to achieve signal amplification and detection, and the detection sensitivity is limited by amplification bias or inhibitors. For some important cases with trace or low abundance samples, such as forensic on-site diagnosis and early diagnosis of tumor with cell-free nucleic acids, it is necessary to achieve highly sensitive POCT of nucleic acids.…”

“…Several studies have managed to reduce the size, price, and complexity of these systems by means of isothermal amplification. 8,9 Some studies have also used end point detection methods, such as nucleic acid lateral flow, to miniaturize the instrument. 10,11 In recent years, some studies have realized electrochemical detection, colorimetric, fluorescent, and surface plasmon resonance detection of samples by taking photos using smart phone, which further improves the mobility of the nucleic acid POCT device.…”