A research group of Hokkaido University, Obihiro University of Agriculture and Veterinary Medicine, Tohoku University, and Tianma Japan Co., Ltd. has developed a portable fluorescent polarization measuring device that can quickly perform biotests such as antibody tests in the field.As an application example, it was demonstrated that avian influenza virus antibody can be detected within 20 minutes.It can also be applied to antibody tests for people infected with the new coronavirus, and is expected to be used at testing sites.
There are highly pathogenic strains of avian influenza, especially the H5 subtype avian influenza virus (H5-AIV).The diseases caused by them are designated as highly pathogenic avian influenza as a domestic animal infectious disease (statutory infectious disease), and the mortality rate when the H5N1 subtype infects humans exceeds 50%.For this reason, rapid subtyping is required when avian influenza occurs, but the current mainstream polymerase chain reaction (PCR) method takes a long time to analyze and has the problem that it can only be measured in a laboratory.There is also an antibody test (immunochromatography method) that can be easily used in the field, but it lacks accuracy and cannot be quantitatively evaluated. Therefore, there is a strong demand for a test technique that can measure easily, quickly, and in large quantities in the field.
Therefore, the research group constructed a fluorescence polarization imaging system by combining a liquid crystal display with the property of controlling the polarization direction of passing light and an image sensor.We have developed a technique to determine the infection history by detecting anti-H5-AIV antibody by fluorescent polarized immunoassay (FPIA).Furthermore, it was designed so that it could be carried to the site, and a portable fluorescence polarization measuring device weighing 5.5 kg was realized.The microchannel chip makes it possible to measure multiple samples at the same time with a small amount of sample.
We also developed reagents used for measurement.Serum collected from birds and measuring reagents are mixed, introduced into a microfluidic device, and set in a portable fluorescent polarizing device to measure the degree of polarization.The anti-H2-AIV antibody can then be detected within 20 minutes with a serum volume of only 5 μL.
According to the research group, the device is being considered for application to the detection of other antibodies and viruses, and is expected to be applied to the detection of antibodies to the new coronavirus (SARS-CoV-2).
