purview of this sub course, but constitute laboratory procedures. However, the
environmental health technician should be familiar with the following general
a. Instruments, containers, and other equipment coming in direct contact with
most specimens must be sterile. The stool specimen is one exception.
b. Material for culture must not be exposed to germicides, disinfectant, or other
c. Specimens should be properly labeled and dated.
d. Specimens should be delivered to the clinical laboratory immediately after
e. Specimens should be inoculated to media immediately after delivery to the
f. To avoid contamination, the specimen should be cultured before making
smears or performing special tests.
g. Material for culture should be obtained before the patient receives antibiotic or
sulfonamide therapy. If this is not possible, the type of therapy should be indicated on
the microbiology request form. SF 553 (Microbiology I) (figure 3-4) is used for most
microbiology requests. SF 554 (Microbiology II) is used for suspected viral, fungal, and
acid-fast bacterial infections.
Figure 3-4. SF 553 (Microbiology I)