112 LABORATORY BACTERIOLOGY 
I 
SENDING TISSUES TO LABORATORIES FOR 
EXAMINATION AND DIAGNOSIS 
It often happens that practitioners wish to send to a labora- 
tory tissues from certain animals for the purpose of diagnosis. 
The diagnosis is made from the results obtained from one or 
more of the following examinations or tests; namely, the micro- 
scopic study of the tissues themselves, bacteriological examina- 
‘tion, including animal inoculations, and specific reactions, such 
as the agglutination test. At certain times in the course of a 
few diseases it is possible for the experienced pathologist to 
tell from the gross lesions the nature of the affection. In order 
that the necessary examinations may be properly carried out 
and the diagnosis made, it is evident that the required tissues 
must be received in a suitable condition. The responsibility 
for obtaining a diagnosis from a laboratory falls very largely 
on the sender of the material. In selecting organs or tissues 
from a diseased animal for examination it is essential to choose 
parts containing the affected tissues. With infectious diseases 
this is especially important. In rabies, for instance, the neces- 
sary parts are in the brain and ganglia, in tuberculosis the 
lesion. may be in any organ, while in anthrax, especially in 
cattle, the disease is general and any organ may be chosen. 
It is also necessary that a sufficient quantity of the tissues be 
sent. 
Specimens should be accompanied by a letter stating what 
tissues were sent and what disease or diseases are suspected. 
This is necessary in order to facilitate the examination. 
In sending tissues to a laboratory the following suggestions 
should be followed : 
1. All tissues that are to be examined bacteriologically or 
in which the disease is to be diagnosed from the examination 
