Microfabricated flow-through PCR device for underwater microbiological study

In this paper, microfabricated gene analysis devices for in situ extremophiles study are presented. The importance of understanding the microorganisms inhabiting in extreme environments (extremophiles) such as deep-sea, deep-subsurface and under glacial lakes are widely recognized. Although the molecular biological technique based on gene analysis is one of the major research methods for environmental microbiology because of its high sensitivity, the technique is time consuming and non-real time in principle. For more detailed and accurate study on environmental microbiology, an in situ genetic analysis method is strongly required. Especially for the study of extremophiles, totally automated and miniaturized analysis systems are essential because of human inaccessibility to such environments. From the engineering point of view, a new research field that relates to the development of miniaturized chemical or biological analysis tools, so called "micro total analysis systems (micro-TAS)" or "lab-on-a-chip", has emerged and rapidly advanced mainly for biochemical and biomedical applications. In this study, a microfabricated chip for the polymerase chain reaction (PCR) as one of the main components of a totally integrated in situ gene analysis system was developed and tested. With the developed PCR chip, 750 bp of DNA fragments were successfully amplified within 20 min from 1450 by DNA fragments of the E. coli whole genome.