Definition/Introduction
Clinical laboratories are healthcare facilities providing a wide range of laboratory procedures that aid clinicians in diagnosing, treating, and managing patients.[1] These laboratories are manned by scientists trained to perform and analyze tests on samples of biological specimens collected from patients.
In addition, clinical laboratories may employ pathologists, clinical biochemists, laboratory assistants, laboratory managers, biomedical scientists, medical laboratory technicians, medical laboratory assistants, phlebotomists, and histology technicians.[2] Most clinical laboratories are situated within or near hospital facilities to provide access to clinicians and their patients.[1]
Classifications of clinical laboratories indicated below reveal that these facilities provide quality laboratory tests that are significant for addressing medical and public health needs.
The list below is non-exhaustive as new laboratory models are emerging:
- Ownership
- Government (usually part of hospitals and medical centers under the Department of Pathology or Laboratory Medicine)
- Private (part of a medical or healthcare institution)
- Function
- General clinical laboratories provide standard diagnostic laboratory tests
- Specialty laboratories provide less commonly used diagnostic and confirmatory tests
- Test specialization
- Clinical chemistry
- Clinical Microbiology
- Hematology
- Blood banking and serology (ie, Immunohematology, Transfusion medicine)
- Histopathology and cytopathology
- Molecular biology
- Public health: providing tests such as water analysis and testing for environmental toxins
- Laboratory network: facilities operated, managed, and supervised by authorities at different levels
- Peripheral laboratories provide routine screening, diagnostic (eg, conventional and rapid diagnostic tests), and follow-up tests for patients, usually within the local community[3]
- Intermediate-level laboratories at the district, provincial, and regional-level facilities
- May conduct additional tests than those provided in peripheral laboratories and can serve as referral laboratories for special cases.
- Aside from performing tests, they perform management and supervisory tasks under specific areas of jurisdiction.[4]
- National reference laboratories, also known as the central level, oversee the overall management of the laboratory network and provide a range of routine and specialized laboratory testing, introducing and phasing new diagnostic tests.[1] They also perform the following functions:
- Policy and program implementation
- Training and development
- Monitoring, evaluation, and research[1]
In the past, the value of clinical laboratories as an integral part of the healthcare system was unrecognized.[5] Over time, more clinicians have recognized the need for laboratory tests to confirm their diagnoses and support monitoring patient response to therapy.[6] Aside from value to individual patients, clinical laboratories were also used for screening and surveillance of diseases. On a larger scale, program managers used some relevant tests as surrogate indicators to assess the progress of public, international, and global health programs.[7]
Laboratory networks were developed across countries and states to foster coordination and collaboration within the specified geographic areas.[8] Quality management systems within these laboratories have recently become significant issues, including standardization of laboratory services, strengthening laboratory systems, and developing new and rapid diagnostic tools. These issues are continually addressed by local and international health authorities and technical experts employing a patient-centered approach.
Clinical laboratories perform testing logically and strictly. Generally, there are 3 phases of the laboratory testing process that each facility should follow. Standard operating procedure manuals and job aids are written for guidance for each phase step: pre-analytical, analytical, and post-analytical.[9] The pre-analytical phase is critical, with over 60% to 70% of laboratory errors occurring in this phase.[10]
Clinical laboratory professionals have embraced technology over the years to derive answers to clinical questions. Modern clinical laboratories use technologies, including spectrophotometry, atomic absorption spectroscopy, cytometry, flame emission photometry, nephelometry, electrochemical, optical sensors, electrophoresis, and chromatography.
- Spectrophotometry is a technique used to measure the absorbance of colored compounds in solution, helping to identify and quantify various substances in blood and body fluids.[11]
- Atomic absorption spectroscopy (AAS): a vital tool in clinical analysis, enabling the measurement of metallic element concentrations within biological fluids and tissues like whole blood, plasma, urine, saliva, brain tissue, liver, hair, and muscle tissue.[12]
- Cytometry is a technique to measure the properties of individual cells, such as size, shape, and DNA content, which can help diagnose and monitor conditions like cancer or genetic disorders.[13]
- Flame emission photometry: a technique to measure the emission of light from a sample excited by a flame, helping to identify and quantify compounds in blood and body fluids.[14]
- Nephelometry is a technique to measure the turbidity of a solution, which helps diagnose and monitor conditions like liver disease or kidney failure.[15]
- Electrochemical technologies are used to measure the electrical properties of a solution, such as pH, conductivity, and redox potential, which help diagnose and monitor conditions like acid-base disorders or electrolyte imbalances.[16]
- Optical sensor technologies: use sensors that detect and measure various properties of a sample using light, such as refractive index or fluorescence, which helps identify and quantify various substances in biological fluids.[17]
- Electrophoresis is a technique to separate and analyze proteins in a sample, which helps diagnose and monitor conditions like multiple myeloma or amyotrophic lateral sclerosis.[18]
- Chromatography is a technique that helps identify and quantify different components in blood and bodily fluids by separating and analyzing compounds in a sample according to their molecular properties, such as size, charge, or shape.[19]
The landscape of clinical laboratory operations has transformed due to the integration of automation, impacting both the analytical and non-analytical aspects. This transition towards automation commenced over 5 decades ago, focusing on automating laboratory test procedures.[20] However, the true leap occurred in the 1990s when non-analytical automation gained momentum, featuring conveyor systems, interfaced analyzers, and automated specimen processing and storage. Automation in the clinical laboratory is classified into 3 categories: manual, stand-alone automation (modular), and total lab automation (TLA).[21]
Automation has a wide-ranging impact, improving laboratory ordering, testing, and reporting processes while eliminating tedious and time-consuming chores.[22] It has ushered in a new era of heightened productivity by streamlining the use of reagents and materials, standardizing operations, and reducing the occurrence of outliers. The efficiency increases production rates and improves accuracy and precision in test results. Automation is a cornerstone in modern clinical laboratories, revolutionizing operations and elevating the overall quality of laboratory testing.[23]
Clinical laboratory specialists perform an array of tasks, including developing and validating new laboratory tests, assessing and defining the analytical and clinical performance, conveying laboratory results to clinicians, offering valuable education and guidance to the clinical team, evaluating the cost-effectiveness and intrinsic value, ensuring strict compliance with regulatory standards, engaging in quality assurance measures, and participating in both basic and clinical research endeavors.[24]
The laboratory professional must maintain the confidentiality of medical information, use resources appropriately, abide by codes of conduct, follow ethical publishing rules, and manage and disclose conflicts of interest.[25]