[In situ enzyme immunoassay for detection of hepatitis A virus].
OBJECTIVE
To establish a more simple and sensitive technique for identification of hepatitis A virus (HAV).


METHODS
HAV vaccine strain H2M20-K and wild-type strain He34 were used to infect KMB17 deploid cells in 96-well tissue culture plates and in situ enzyme immunoassay was used to detect viral infection with specific HA monoclonal antibody, A(OD) value of 1.8 was used as positive indicator.


RESULTS
Observation of viral replication showed the peak titer of viral infectivity reached at 20-25 days after viral infection, which was 4-6 day searlier than that of ELISA endpoint assay. Comparing the viral infectivity titers of 13 individual samples, the two methods revealed no significant statistic difference (t = 1.13, P > 0.05). Our tests showed that in situ EIA could better reflect the results of neutralization and 5 HAV positive isolates were directly isolated from 12 faecal samples after the first passage culture.


CONCLUSIONS
Although the sensitivities of the two tests were similar, the direct detection of virus/cell system with in situ EIA showed simple, easy to operate and reproducible, it may replace the conventionally used ELISA endpoint assay for identification of HAV, even for the other viruses.
Hou
Z
Z
Institute of Medical Biology, Chinese Academy of Medical Sciences, Kunming 650107.
Yan
J
J
Long
R
R
D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D030041:Hepatitis A virus / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008168:Lung / Q000166:cytology / Q000196:embryology / Q000821:virology