Abstract

Pathogen analysis on Chip: Sample Enrichment, Preparation and Detection

Gerald Urban, Professor, Albert Ludwigs Universität Freiburg

At present, all intermediate acute testing of metabolic parameters are made using small point of care (POC) analysers which work with miniaturized sensor arrays. However pathogen detection relies nowadays on methods which were invented 100 years ago. Molecular biological procedures for pathogen detection and testing of antibiotic resistance are entering the clinical routine very slowly. However, POC devices based on oligonucleotide detection would be very advantageous to identify infection at a very early stage to initiate personalized therapeutic procedures. Using special microfluidic lab-on-chip chip based systems structures can perform such oligonucleotide based pathogen detection assays. With special structures called “phase guides” the defined filling and handling of biological samples on chip can be accomplished. Enrichment, lysis, purification and isothermal amplification of cell specific oligonucleotides can be done on chip without moving parts and using only 5µl analyte volumes. The biological targets are small RNA biomarkers which are very selective to identify bacteria as well as viruses. To achieve such tasks the integration of free flow electrophoresis, gel electrophoresis and the integration of actuating and sensing structures in a microfluidic device are mandatory. Because the aim is the application of such portable devices for environmental control especially in developing countries an easy to use system without any moving parts are intended. Therefore also electrophoretic pumps were developed to transport analyte and reagents in a confined microfluidic chip. The different modules for enrichment, pumping, purification and detection were miniaturized and partially integrated and successfully tested with pathogens.