Use the following choices to answer questions 7–9.
a. direct fluorescent antibody
b. indirect fluorescent antibody
c. rabies immune globulin
d. killed rabies virus
e. none of the above


Test used to identify rabies virus in the brain of a dog.

Verified step by step guidance

1. Identify the purpose of the test: The goal is to detect the presence of the rabies virus in the brain tissue of a dog.
2. Consider the nature of the rabies virus: Rabies is a viral infection that affects the central nervous system, and it can be detected using specific antibodies.
3. Review the test options: Direct fluorescent antibody (a) and indirect fluorescent antibody (b) tests are commonly used for detecting viral antigens in tissues.
4. Understand the direct fluorescent antibody test: This test involves applying a fluorescently labeled antibody directly to the tissue sample to bind to the rabies virus antigens, if present.
5. Determine the most suitable test: Given the need to identify the rabies virus in brain tissue, the direct fluorescent antibody test (a) is typically used for this purpose.

Key Concepts

Fluorescent Antibody Techniques

Fluorescent antibody techniques are immunological methods used to detect specific antigens in tissues or cells using antibodies labeled with fluorescent dyes. In the context of rabies virus identification, these techniques can be categorized into direct and indirect methods, allowing for visualization of the virus in tissue samples under a fluorescence microscope.

Direct vs. Indirect Fluorescent Antibody Tests

Direct fluorescent antibody tests involve the use of antibodies that are directly conjugated to a fluorescent dye, allowing for immediate visualization of the target antigen. In contrast, indirect tests use a primary antibody to bind the antigen and a secondary antibody, which is fluorescently labeled, to amplify the signal, providing greater sensitivity in detecting the rabies virus.

Rabies Virus Identification

Identifying the rabies virus typically involves examining brain tissue from suspected infected animals, such as dogs. The direct fluorescent antibody test is a common method used for this purpose, as it allows for rapid and accurate detection of the virus, which is crucial for public health and treatment decisions following potential rabies exposure.