Most large labs have different departments: Chemistry, Hematology,
Urinalysis, Blood Bank, Serology, Microbiology. These are in the clinical
laboratory.

There can be other departments in a clinical lab depending on how large the
lab is or what their focus is. Some labs have Toxicology departments.
Molecular is the new up and coming area in many labs. Our lab also has a
separate Virology Department. Some huge micro labs have separate Mycology
and Mycobacteriology Departments. Some big ones even have Parasitology
Departments.

Cultures of all types go into Microbiology. The cultures are planted on
special media depending on the type of culture. If special work is ordered
(fungal=Mycology, acid fast bacteria=Mycobacteriology) then these specimens
have special processing for this type of testing. Virology specimens also
require special processing depending on type of specimen.

Blood work is done mostly in Chemistry, Hematology, and other departments
that deal with blood specimens. Microbiology only deals with blood specimens
when they are in blood culture bottles (blood put into broth to see if there
is bacteria growing in a patient's blood stream. If there is, the patient is
septic and this is life threatening).

There is not room enough here to go into all the testing that Chemistry,
Hematology, etc. does. Most of this is done on big analyzers nowadays, and
the days of hand chemistry is long gone. Likewise, Hematology is performed
on big analyzers, although certain parameters are hand checked. It's been
many years since I've worked in anything but micro, so my knowledge of
current methods in other parts of the lab is very limited nowadays.

Blood bank is where blood is crossmatched for transfusion purposes. It can
be a busy place, depending on how many surgeries and traumas a hospital
handles.

When you get "across the hall" you get into Pathology proper. The
pathologists, who are MD's, oversee the entire laboratory. There are
clinical pathologists (pathologists trained to oversee all clinical lab
departments, but they also do pathologist stuff also) and anatomic
pathologists (those that deal with reading tissues only and do not deal with
clinical lab administration).

Histology is the department that receives all tissues removed in surgery.
These tissues have both a "gross" examination and a "microscopic"
examination. Gross is performed by the pathologist with the assistance of a
Histology tech. They measure all tissues (some are quite large) and dictate
measurements and appearances into a tape which is later transcribed by
Pathology transcription personnel. They cut certain sections to be placed
into cassettes for further microscopic examination. The Histology tech keeps
track of specimen numbers, etc. while the pathologist places the tissue
pieces into cassettes for further paraffin mounting. They place these
cassettes into a tissue processor overnight. Then the histo techs (often
arriving around 4:30 a.m.) will cut sections of these processed cassettes
for mounting onto slides. They come in early to have all staining and
mounting done for the pathologists to read the slides when they arrive later
in the morning. This is why biopsy results are not instantaneous and
sometimes take 2-3 days or more to come back. Some difficult slides are
referred to other pathologists for their opinion. No pathologist will stick
his neck out if he's not sure of what he's looking at and they get second
opinions sometimes on what they see.

Cytology is a deparment that looks for abnormal cells. They are the ones
that read PAP smears. Registered Cytologists look at specially prepared
slides from PAPs, and also slides of cells from any type of body fluid
(pleural, ascitic, abdominal) and other specimens (like sputum specimens for
cancer cells). If they screen them and find abnormal cells, these slides are
passed on to pathologists to finalize the readings.

So, the Pathology Department consists of the clinical lab and the
Histology/Cytology laboratories. They are usually pretty separate as far as
workers go, as the requirements for all the jobs are different. Medical
technologists receive training in all parts of the clinical lab (but not
Pathology, as that is separate). Once out of training, many stay working as
generalists, others specialize in certain departments. I have specialized in
microbiology most of my 32 years. I've done general lab for about 4 years,
marketing for two, and micro the rest. I haven't done anything except micro
since 1988.

Hope this helps.

Judy Dilworth, M.T. (ASCP)
Microbiology