Introduction to the Clinical Laboratory

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The page below is a sample from the LabCE course An Introduction to the Medical Laboratory, Part 1. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

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Introduction to the Clinical Laboratory

Within the clinical laboratory, patient blood, body fluid, other specimens are tested and laboratory reports are generated. Commonly requested tests for the clinical laboratory are performed in-house while less commonly requested tests are sent to a reference laboratory.
The clinical laboratory can be broken down into various departments, each of which is staffed by medical laboratory scientists (MLS) and medical laboratory technicians (MLT). MLSs and MLTs are trained to perform specific tests and to operate and monitor automated instruments within their department(s). Each department is overseen by a qualified supervisor or a lead technologist. These supervisors are typically MLSs that have experience with the specific laboratory techniques and automated instruments in that department.
Departments within the clinical laboratory include data management, specimen collection and processing, hematology, chemistry, transfusion services, microbiology, and molecular diagnostics. In all of these departments, specialized automated instruments ensure analysis quality and deliver results to the patient's electronic medical record (EMR).
The data management department is the area where the Laboratory Information System (LIS) and its communication with analyzers are managed.
The specimen collection and processing department is the area where specimens are collected and processed before they are submitted to the necessary departments for testing. Blood is the most common specimen collected in the department and received from out-patient collection areas. Tasks in the specimen collection and processing department are also performed by phlebotomists and medical laboratory assistants (MLA).
The hematology department is the area where cellular components of the blood - red blood cells, white blood cells, and platelets - are tested. Coagulation, or the ability of the blood to clot, is also tested in this department.
The chemistry department is the area where blood plasma and serum are tested for various analytes. An example of an analyte is an electrolyte. Electrolytes, such as sodium (Na+), chloride (Cl-), and potassium (K+), are analytes important for diagnosing diseases and other conditions. Urinalysis, or the analysis of urine, is also performed in this department.
The transfusion services department is the area where blood donor units are matched with blood recipients. The transfusion services department receives donor blood components and tests them for compatiblity with patient samples. It requires high quality control, since erroneous compatibility results can cause serious negative outcomes for the patient.
The microbiology department is the area where microorganisms within a patient specimen are grown for identification, otherwise known as "culturing." After the microorganisms are cultured, they are tested for antibiotic sensitivity, which reveals the most effective antibiotic treatment for a patient's infection. Testing in the microbiology department is also performed by PhDs.
The molecular diagnostics department is the area where molecules like DNA and RNA are tested to produce diagnostic results. The most common laboratory technique is the polymerase chain reaction (PCR), which helps identify bacterial or viral infections including HPV and COVID-19.
3. Gathany, James."This photograph depicted an Enteric Diseases Laboratory Branch (EDLB), Public Health scientist, who was testing bacterial samples for their antimicrobial susceptibility." CDC Public Health Image Library, 2019, https://phil.cdc.gov/Details.aspx?pid=23182. Accessed August 15, 2020.
4. Gathany, James."This photograph depicted an Enteric Diseases Laboratory Branch (EDLB), Public Health scientist, who was setting up a molecular test called a polymerase chain reaction (PCR), in order to detect specific bacterial DNA in a sample." CDC Public Health Image Library, 2019, https://phil.cdc.gov/Details.aspx?pid=23174. Accessed August 15, 2020.

An MLS testing bacterial cultures from specimens for
antimicrobial susceptibility in the microbiology department (3).
An MLS preparing a specimen for a polymerase chain reaction (PCR)
in the molecular diagnostics department (4).