Testing performed in the Laboratory is very diverse.
Here’s an overview:
This Department is responsible for identifying “germs” which may cause infections. Specimens are delivered to this department and the microbiologist puts small portions of the specimen on, or in, special material that allow the germs to grow rapidly and in large numbers. After the germs have been allowed to grow for some time, often hours or days, the microbiologist tests them with different chemicals. Depending on the results of these chemical tests, the microbiologist can identify what type of germ is growing and what drugs may be used to treat the infection.
This department has two broad functions. The first is to count the number of several different types of blood cells. From the counting of these cells the hematologist can determine if the patient is “anemic” (has a low red blood cell count) or if the patient has a bacterial or viral infection. By looking at the blood cells under a microscope, the hematologist can also observe clues to several other conditions that may afflict a patient, such as liver disease or bone marrow disorders.
Coagulation testing is also performed in the Hematology department. Technicians will add special chemicals to portions of a patients blood specimen and determine how long it takes for it to clot. Clinicians monitor certain “blood thinners” with results of this testing. Blood clotting disorders can also be diagnosed from the results of these tests.
This department performs testing that measures the concentration of certain chemical compounds in blood and other body fluids. Concentrations of therapeutic drugs, like Digoxin and Dilantin, are determined in this department. In fact, the broadest variety of testing is performed in the Chemistry department. Many people are familiar with tests such as glucose, cholesterol, triglyceride, and TSH (thyroid stimulating hormone). Results from combinations of chemistry tests can help clinicians diagnose many different conditions, including kidney disease, heart attack, and diabetes. Results from chemistry tests can also be used to monitor the progress of these conditions.
This department is responsible for “typing” and “crossmatching” blood and blood products. The “Blood Type” that many of us are familiar with, is just a small portion of the different blood-type groups. Sometimes people develop antibodies to certain types of blood cells that can cause them to react to, or reject, a transfusion of this specific type of blood. This is why it is important to test a patient’s blood specimen for unexpected antibodies before they receive a blood transfusion.
Many products other than red blood cells are managed in the Blood Bank.
Plasma-the liquid portion of the blood which contains chemical compounds, or “clotting factors”, that are important to control bleeding
Platelets-small blood cells that first serve to “plug” a cut and stop bleeding
Leukocytes-white blood cells that are given to patients when these cell counts drop to dangerous levels
This department receives various tissue specimens (such as moles, intestinal polyps, and gall bladders) and evaluates its structure. This evaluation involves observations on overall physical characteristics (size, shape, color, etc.) all the way down to the structure of individual cells. This evaluation can determine the normal or abnormal development of the tissue, and can rule-out or diagnose conditions such as cancer. A tissue specimen evaluated in the histology department is often referred to as a biopsy.