RFFIT stands for Rapid Fluorescent Foci Inhibition Test. It is a serum neutralization (inhibition) test, which means it measures the ability of rabies specific antibodies to neutralize rabies virus and prevent the virus from infecting cells. These antibodies are called rabies virus neutralizing antibodies (RVt4A). The RFFIT does not measure the amount of rabies specific antibodies but the neutralizing activity of the antibodies present in the serum. In the test, your serum (the non-cellular portion of your blood) is first diluted fivefold (1 part serum in 4 parts diluent). Further (serial fivefold) dilutions are performed, each of which contain less and less of your serum. These serum dilutions are mixed with a standard amount of live rabies virus and incubated. Whatever RVNA is present will neutralize the virus. Next, some tissue culture cells are added and the serum/virus/cells are incubated together. Whatever rabies virus is left (i.e., that which has not been neutralized by the antibody in your serum), will infect the cells and this can be seen under the microscope through the use of specific staining. Calculation of the endpoint titer is made from the percent of virus infected cells observed on the slide.
What does your result tell you? The RFFIT test can be used in two ways: To determine an RVNA titer (e.g.,1:5) or to determine a value for R/NA concentration (e.g.,0.1 IU/mL). The IU stands for International Unit and is calculated from the titer by comparing it against a standard reference serum. We use the following formula: Sample titer divided by the reference serum titer, multiplied by the IU/mL value of the reference serum. Rabies Antibodies test is performed on a sample of blood to measure the level of Rabies Antibodies in the blood.It is performed to confirm Muscle Spasm and also during the treatment and after the treatment of Fever, Hygrophobia and Muscle Spasm.
No special preparation is needed for Rabies Antibodies Elisa Blood. Inform your doctor if you are on any medications or have any underlying medical conditions or allergies before undergoing Rabies Antibodies Elisa Blood. Your doctor depending on your condition will give specific instructions.
|UNISEX||All age groups||The antibodies are not normally present. They are detected in case of an infection|