Keywords: sample preparation, POCT, Cartridge, microfluidic chip
Summary:The fast and sensitive detection tools have been highly required in food, environmental, and clinical fields because of recent frequent outbreak of pathogen in the world. Even though various sensing tools based on protein and/or nucleic acids have been already developed and commercialized, only a few methods could be applied in pathogen diagnostics due to the complexity of sample. To employ nucleic acid based diagnostic methods to Point-of-care technology, preferentially sample preparation processes to extract, purify, and concentrate nucleic acid from biological complex sample are required to be simplified and automated. The most representative examples are GeneXpert system of Cepheid and Biofire system of Biomerieux. However, more sophisticated procedures may be required to treat large amount of complex samples such as environmental and biological samples. For example, in order to measure the infectious bacteria in a soil sample using the nucleic acid-based method, humic acid must first be removed. In addition, in order to measure infectious bacteria in the river, the infectious bacteria must be preferentially concentrated in the 100 L sample. For 20 years, gold standard isolation method of nucleic acid from bacteria/virus in various samples is “boom technology”, which uses high chaotropic salt such as guanidine thiocyanate and organic solvent like ethanol. Even though its powerful extraction capability of DNA or RNA from the pathogen, it has some drawback to be applied to all clinical fields. The enrichment or concentration steps of pathogen are essentially required before getting nucleic acid. Second, it can’t be applied to the pneumatic-type lab on a chip, which is fully automatically operated from a sample to an answer. These drawbacks may induce false positive or negative errors by cross-over contamination. Here I would like to introduce some chips and cartridges that can easily and conveniently measure infectious bacteria from several environmental and biological samples.