Biotin-labeled antigen sandwich enzyme-linked immunosorbent assay (BLA-S-ELISA) for the detection of Japanese encephalitis antibody in human and a variety of animal sera.

The research article presents a method to detect Japanese encephalitis antibodies in humans and various animals using a biotin-labeled antigen sandwich enzyme-linked immunosorbent assay (BLA-S-ELISA).

Methodology

• The research employs a method that involves the use of a biotin-labeled antigen (BLA) in a sandwich enzyme-linked immunosorbent assay (S-ELISA).
• This is used to detect antibodies related to Japanese encephalitis (JE) in various types of animal sera.
• The JE antigen is fixed onto the wells of a microplate and is bound to a specific antibody.
• This antibody reacts with a peroxidase-labeled avidin conjugate and azino-di-(3-ethylbenzthiazolin sulfonic acid) (ABTS) used as a substrate.

Results and Findings

• This BLA-S-ELISA method was able to simultaneously detect JE antibodies in all hemagglutination inhibition (HI) positive sera from various sources including humans, swine, monkeys, horses, cattle, rabbits, rats, mice, and pigeons. This was achieved by using the same reagents under identical test conditions.
• In serums derived from humans and swine, the antibody titers obtained via BLA-S-ELISA aligned well with HI antibody titers. This suggests the reliability and accuracy of the test in these subjects.
• The new method was found to have greater sensitivity for IgM antibodies compared to IgG antibodies.

Significance of Findings

• The research demonstrated an impressively low non-specific reaction in BLA-S-ELISA, enabling the cut-off titer for the assay to be as low as a 1:2.5 of serum dilution for positive antibody detection.
• This suggests that the BLA-S-ELISA could potentially be a valuable diagnostic tool for detecting JE antibodies in serum samples from various animals and humans due to its sensitivity and low non-specific reaction rate.