A medical laboratory or clinical laboratory is a laboratory where tests are done on clinical specimens in order to get information about the health of a patient as pertaining to the diagnosis, treatment, and prevention of diseases.
Laboratory medicine is generally divided into four sections, and each of which is further divided into a number of units. These four sections are:
Anatomic Pathology: units are included here, namely histopathology, cytopathology, and electron microscopy. Academically, each unit is studied alone in one course. Other courses pertaining to this section include anatomy, physiology, histology, pathology, andpathophysiology.
Clinical Microbiology: This is the largest section in laboratory medicine; it encompasses five different sciences (units). These includebacteriology, virology, parasitology, immunology, and mycology.
Clinical Biochemistry: Units under this busy section are instrumental analysis, enzymology, toxicology and endocrinology.
Hematology: This small, yet busy, section consists of two units, which are coagulation and blood bank.
Genetics is also studied along with a subspecialty known as cytogenetics.
Distribution of clinical laboratories in health institutions varies greatly from one place to another. Take for example microbiology, some health facilities have a single laboratory for microbiology, while others have a separate lab for each unit, with nothing called a "microbiology" lab.
Laboratory equipment for hematology(black analyser) and urinalysis (left of the open centrifuge).
Here's a detailed breakdown of the responsibilities of each unit:
Microbiology receives almost any clinical specimen, including swabs, feces, urine, blood,sputum, cerebrospinal fluid, synovial fluid, as well as possible infected tissue. The work here is mainly concerned with cultures, to look for suspected pathogens which, if found, are further identified based on biochemical tests. Also, sensitivity testing is carried out to determine whether the pathogen is sensitive or resistant to a suggested medicine. Results are reported with the identified organism(s) and the type and amount of drug(s) that should be prescribed for the patient.
Parasitology is a microbiology unit that investigates parasites. The most frequently encountered specimen here is faeces. However, blood, urine, sputum, and other samples may also contain parasites.
Virology is concerned with identification of viruses in specimens such as blood, urine, andcerebrospinal fluid.
Hematology works with whole blood to do full blood counts, and blood films as well as many other specialised tests.
Coagulation requires citrated blood samples to analyze blood clotting times and coagulation factors.
Clinical Biochemistry usually receives serum or plasma. They test the serum for chemicals present in blood. These include a wide array of substances, such as lipids, blood sugar, enzymes, and hormones.
Toxicology mainly tests for pharmaceutical and recreational drugs. Urine and blood samples are submitted to this lab.
Immunology/Serology uses the concept of antigen-antibody interaction as a diagnostic tool. Compatibility of transplanted organs is also determined.
Immunohaematology, or Blood bank determines blood groups, and performs compatibility testing on donor blood and recipients. It also prepares blood components, derivatives, and products for transfusion. Regulated by the FDA since giving blood is considered a drug, this unit determines a patient's blood type and Rh status, checks for antibodies to common antigens found on red blood cells, and cross matches units that are negative for the antigen.
Urinalysis tests urine for many analytes. Some health care providers have a urinalysis laboratory, while others don't. Instead, each component of the urinalysis is performed at the corresponding unit. If measuring urine chemicals is required, the specimen is processed in the clinical biochemistry lab, but if cell studies are indicated, the specimen should be submitted to the cytopathology lab, and so on.
Histopathology processes solid tissue removed from the body (biopsies) for evaluation at the microscopic level.
Cytopathology examines smears of cells from all over the body (such as from the cervix) for evidence of inflammation, cancer, and other conditions.
Electron microscopy prepares specimens and takes micrographs of very fine details by means of TEM and SEM.
Genetics mainly performs DNA analysis.
Cytogenetics involves using blood and other cells to get a karyotype. This can be helpful in prenatal diagnosis (e.g. Down's syndrome) as well as in cancer (some cancers have abnormal chromosomes).
Surgical pathology examines organs, limbs, tumors, fetuses, and other tissues biopsied in surgery such as breast mastectomys.