Detecting anti-virus antibody in 20 minutes

Researchers have succeeded in detecting anti-avian influenza virus antibody in blood serum within 20 minutes, using a portable analyzer they have developed to conduct rapid on-site bio tests. If a suitable reagent is developed, this technology could be used to detect antibodies against SARS-CoV-2, the causative virus of COVID-19.

Avian influenza is a poultry disease caused by influenza A virus infection. Rapid initial response for a suspected infection and continuous surveillance are essential to mitigate the damage from highly pathogenic, transmittable pathogens such as avian influenza viruses.

Generally, the polymerase chain reaction (PCR) method is used to detect the viral genome, but its complicated procedure requires a considerable amount of time. Another method involves detecting antibodies produced in the body in reaction to virus infection. However, widely used antibody detection methods can be inaccurate because the antibodies' existence is generally determined by eyesight.

Researchers have developed a new method and analyzer capable of rapid, facile and selective detection of antibodies. The method is based on conventional fluorescence polarization immunoassay (FPIA) but applies a different measurement mechanism to make the analyzer much smaller and portable. The analyzer weighs only 5.5 kilograms.

The combined use of liquid crystal molecules, an image sensor and the microfluidic device makes it possible to simultaneously examine multiple samples and reduces the volume of each sample required. Liquid crystal molecules are capable of controlling the polarization direction of fluorescent light, while the microfluidic device has a number of microchannels as a measurement vessel.

The group also developed a reagent to detect anti-H5 avian influenza virus antibody, a fluorescein-labeled protein that binds only with the antibody. The reagent was made by reproducing hemagglutinin (HA) protein fragments, which are expressed on the surface of H5 avian influenza virus, through gene recombination and by labeling fluorescent molecules to the fragments.

See:

Keine Nishiyama, Yohei Takeda, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Yutaka Yonezawa, Kunitoshi Imai, Haruko Ogawa, Manabu Tokeshi. Rapid detection of anti-H5 avian influenza virus antibody by fluorescence polarization immunoassay using a portable fluorescence polarization analyzer. Sensors and Actuators B: Chemical, 2020; 316: 128160 DOI: 10.1016/j.snb.2020.128160

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)