Fluorometric assay for measurement of viral neuraminidase--application to the rapid detection of influenza virus in nasal wash specimens.
A sensitive assay was developed for the measurement of neuraminidase with use of the 4-methylumbelliferkyl-alph-ketoside of N-acetyl-neuraminic acid as a fluorescent substrate. Neuraminidase activity was detected in preparation containing small quantities of cultivated influenza virus as well as in some nasal wash specimens from human volunteers experimentally infected with influenza A/Alaska/78 virus. Activity due to influenza viral neuraminidase could be distinguished from activity due to bacterial or mammalian (fibroblast) neuraminidase by means of enzyme inhibition with ethylenediaminetetraacetate, a chelating agent. The same substrate could be used in a solid-phase assay to determine the antigenic type of the influenza viral neuraminidase. The fluorescent neuraminidase assay takes 2-4 hr to perform and uses equipment available in many laboratories. Thus, it offers promise for the rapid detection of influenza viruses in cell cultures and clinical specimens.
D000818:Animals; D003587:Cytomegalovirus; D004797:Enzyme-Linked Immunosorbent Assay; D005453:Fluorescence; D006801:Humans; D009980:Influenza A virus; D007251:Influenza, Human / Q000175:diagnosis*; D008459:Measles virus; D009297:Nasal Mucosa / Q000378:metabolism*; D009439:Neuraminidase / Q000276:immunology / Q000378:metabolism*; D018108:Respirovirus; D018139:Simplexvirus; D013296:Streptococcus pneumoniae
D009439:Neuraminidase