Rabies Vaccine Response End Point Titer : 5789

RABTQ or 5789

RFFIT

Please note: Referral lab will not release results unless collection date is provided.

Preferred Specimen
2 mL serum

Minimum Volume
1 mL

Refrigerated.

Room temperature: Unacceptable; Refrigerated: 10 days; Frozen: 30 days

Gross hemolysis, Date drawn not provided

Monday & Wednesday & Friday

30 days (From receipt at perfroming Laboratory)

The acronym RFFIT stands for Rapid Fluorescent Focus Inhibition Test. The test measures the ability of antibodies that may be present in a sample to neutralize and block rabies virus from infecting the cells used in the test. These antibodies are called rabies virus neutralizing antibodies (RVNA). In the test, serum (the non-cellular portion of a blood sample) 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 the sample. The serum dilutions are mixed with a standard amount of live rabies virus and incubated. If RVNA are present in the sample, they will bind to the virus. Tissue culture cells are then added and incubated with the test sample and virus. Whatever rabies virus that may not have been neutralized by the antibody in the sample will then infect the cells. These foci of infection in the cells can then be seen under the fluorescent microscope. If there are a lot of infected cells, there is very little antibody; conversely, if antibodies are high, the cells will have very little evidence of infection. The endpoint titer is calculated from the percent of virus-infected areas observed within the wells containing the various dilutions of the sample on the slide.