Real time observation of binding of measles virus to Vero cells and neutralization of measles virus by human immunoglobulin using optical biosensor--a new real time diagnosis system for viral infections

Abstract

An optical biosensor to monitor molecular intractions was developed. This system made possible to observe reactions with a few minutes. We tried to apply this system for rapid diagnosis of viral infections. Measles virus propagated in our laboratory and crude rabbit anti-measles antiserum were used. A commercially available human immunoglobulin was used as a representative of patient sera. A crude rabbit anti-measles antiserum was fixed on the reaction surface of aminosilane coated cuvette, and specific binding of measles virus to this antibody was monitored. Specific purified IgG antibody was known to give as high sensitivity as the conventional culture method. But the sensitivity by crude antibody was found to be 1/10 in the sensitivity. This might be caused by the masked effects on specific antibody to the contaminated high amounts of non-specific proteins. None purified polyclonal antisera for most of the viruses are commercially available, and 10-20 times highly concentrated antibody solutions could be used for this titrations. Estimated anti-measles antibody titer of the commercial available human immunoglobulin by biosensor system was found to be the same as that by the conventional culture method. It was suggested that 1 X 10(3) virus particles/ml in the test solutions could be detectable and titerable by using commercially available specific anti-viral antibody in real time, and the viral infections could be diagnosed within an hour.