Antibodies to bovine serum albumin in human sera: problems and solutions with casein-based ELISA in the detection of natural Japanese encephalitis virus infections.
An ELISA system for measuring antibodies to nonstructural protein 1 (NS1) of Japanese encephalitis virus has already been established. This system uses an ELISA diluent containing casein, instead of bovine serum albumin (BSA). During a survey, we found that 21 (21%) of 102 children aged 1-5 years, who had no history of Japanese encephalitis vaccination and were without detectable neutralizing antibodies, showed positive results with this ELISA system. Western blotting analysis showed that sera from 19 (91%) of these 21 subjects had antibodies to BSA, but not NS1. These sera reacted with BSA antigen remaining in immunoaffinity-purified NS1 antigen. One solution to this problem was to reduce the BSA level to < or =1% of the NS1 amount. Another was to use a control well sensitized with BSA with the same amount as that contained in the NS1 antigen preparation.
Konishi
Eiji
E
Department of International Health, Kobe University Graduate School of Health Sciences, Kobe 654-0142, Japan. ekon@kobe-u.ac.jp
Kitai
Yoko
Y
Nishimura
Koichi
K
Harada
Seiya
S
D000914:Antibodies, Viral / Q000097:blood*; D002364:Caseins / Q000276:immunology*; D002675:Child, Preschool; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D012710:Serum Albumin, Bovine / Q000276:immunology*; D014773:Virology / Q000379:methods*
D000914:Antibodies, Viral; D002364:Caseins; D012710:Serum Albumin, Bovine