Which of the following is a good test to detect rabies virus in the brain of a dog?
a. Agglutination
b. Hemagglutination inhibition
c. Virus neutralization
d. Direct fluorescent antibody

Verified step by step guidance

1. Understand that rabies virus detection in brain tissue requires a test that can directly identify viral antigens or the virus itself in the sample.
2. Review the options: agglutination tests detect antibodies or antigens in fluids but are not typically used for direct detection in brain tissue.
3. Hemagglutination inhibition tests are used to detect antibodies against viruses that cause hemagglutination, but rabies virus does not cause hemagglutination, so this test is not suitable.
4. Virus neutralization tests measure the ability of antibodies to neutralize virus infectivity, usually performed on serum samples, not directly on brain tissue.
5. Direct fluorescent antibody (DFA) test uses fluorescently labeled antibodies that bind specifically to rabies virus antigens in brain tissue, making it a rapid and reliable diagnostic method for detecting rabies virus in brain samples.

Key Concepts

Rabies Virus Detection Methods

Detecting rabies virus in brain tissue requires specific diagnostic tests that identify viral antigens or genetic material. Common methods include direct fluorescent antibody (DFA) testing, which detects viral proteins in tissue samples, and other serological tests that detect antibodies or viral particles in fluids.

Direct Fluorescent Antibody (DFA) Test

The DFA test uses fluorescently labeled antibodies that bind specifically to rabies virus antigens in brain tissue. Under a fluorescence microscope, infected cells emit bright signals, making DFA the gold standard for rapid and accurate post-mortem rabies diagnosis in animals.

Serological Tests: Agglutination, Hemagglutination Inhibition, and Virus Neutralization

Agglutination tests detect antibodies or antigens by clumping reactions, hemagglutination inhibition measures antibodies that block virus-induced red blood cell clumping, and virus neutralization assays assess the ability of antibodies to inhibit viral infectivity. These are generally used for serum samples, not direct brain tissue detection.