No 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.