This detection method effectively utilizes the characteristics of the LAMP method, i.e., a large amount of amplification product can be synthesized in a short time while maintaining high specificity. Since a large amount of amplification product is created by the LAMP reaction, precipitate of a size that can be easily confirmed with the eyes is generated when PEI is added to the LAMP reaction solution. Moreover, the fact that the amplification is highly efficient means that the amount of labeled probe for detection that can be added is large. As a result of these characteristics, the LAMP reaction followed by addition of PEI yields precipitate with a clear color and in a size that can be identified visually, as shown in the photograph in Figure 2 . Furthermore, the fact that the amount of the amplification product is large means that the range of the optimum amount of PEI necessary to generate the insoluble complex is wide. Thus, a precise system for adding the PEI solution is not necessary. This will contribute to simplification of g-POCT devices that use this detection method. In the case of PCR, the most widely used gene amplification method, the amount of amplification product is usually 1/20 or less that of LAMP [9] . Consequently, in order to apply this method to PCR, a device for rapidly cycling the temperature to perform PCR, a high-luminance fluorogenic reagent, a system for washing unreacted probes, and a system for accurately dispensing PEI would be necessary. This would likely be an obstacle to putting to practical use a simple, inexpensive g-POCT device for genetic testing.