The specimen was frozen by mistake. Can it still be tested?
The specimen may still be submitted for testing; however, freezing and thawing of brain material causes two problems for rabies testing. (1) The thawed brain will be very soft and mushy making it difficult to identify the various parts of the brain. If the parts can be identified a specimen will be tested as normal. If the parts cannot be adequately identified, the material will be tested and reported “positive” if the material appears positive, but will be reported “unsatisfactory” if the material does not appear positive. (2) Freezing and thawing of the brain may actually inactivate the virus. This is not a problem for the direct fluorescent antibody test– this test is not dependent on viable virus but only on the presence of viral antigen, however, it may compromise additional testing, such as culture for confirmation of specimens that are difficult to interpret by the direct fluorescent antibody test.
