The Medical Laboratory Scientist
The Medical Laboratory Scientist (also known as Biomedical Scientist) is a professional who combines knowledge about human biology, chemistry and technology to carry out analytical tests.
In the medical field, the profession operates behind the scenes, in medical laboratories where testing on human samples is performed with standardised procedures. By liaison with other health care professionals, results help in diagnosis of disease, decide on treatment regimes, and monitor patient health. Professionals are also involved in medical research contributing to medical breakthroughs and innovative discoveries.
Since the Medical Laboratory Science profession offers a considerable contribution to the delivery of health care services, it keeps patient care and patient safety at the core of its values. This is achieved by maintaining professional knowledge throughout the career, be proficient in using and maintaining specialised lab equipment to ensure high quality results, prioritising workloads to achieve efficient turn around times, support laboratory quality management systems and operate within regulations.
Medical Laboratory Scientists may choose to specialise in one of the following areas of Biomedical Sciences:
Investigations of blood components, blood producing organs and blood diseases
The Haematology laboratory is responsible for the assessment of blood cell composition and blood formation and any disorders affecting these processes. Some examples of these tests are 'Full blood count', a count of the total number of red blood cells, white blood cells and platelets present in blood. A peripheral 'Blood film' involves blood smeared over a glass slide for viewing under the microscope. Blood is stained with specific dyes and the number, shape and size of blood cells together with the presence of any abnormal or immature cells are noted. These blood films may also detect blood parasites such as Malaria, Toxoplasmosis, and Microfiliariasis. The bone marrow is the site of 'Haemopoiesis', a blood-forming organ, and examination occurs in situations when there are abnormalities in perpipheral blood such as the presence of leukaemia cells. The Iron status, an important element for blood production, is also assessed using specialised stains to identify the iron stores in the bone marrow.
Flow cytometry, another Haematology speciality, measures multiple characteristics of individual cells. These include cellular size, complexity and the antigenic composition of the different blood cells. During maturation within the bone marrow, the different blood cells acquire and loose antigens, which give the individual blood cells a unique phenotype. Flow cytometry uses fluorochrome labelled antibodies to identify these antigens, thus assigning cellular lineage and stage of maturation. Some clinical applications of Flow cytometry include Identification of leukaemias and lymphomas from blood, bone marrow, tissue specimens and body fluids, The immunologic monitoring of HIV-infected individuals, and the assessment of structural and functional properties of erythrocytes, leukocytes, and platelets
The Clinical Coagulation laboratory is concerned with the blood’s ability to clot and how long it takes to clot. This is important to ascertain a balance between activation of the Coagulation system and the prevention of thrombosis, which is unnecessary blood clot formation.
Coagulation tests ensure that when there is injury, the body can stop the bleeding and that such activation does not occur spontaneously. In fact, they are routinely requested before surgery. Coagulation tests are also useful in monitoring people who take medicines that affect clotting ability. For instance, the Prothrombin Time (PT/INR) is used to monitor Warfarin therapy, whilst the Activated Partial Thromboplastin Time (APTT) is used to monitor Heparin therapy. Other more specialised tests measure various Coagulation proteins and their function.
Haematology Molecular Diagnostics
Molecular Diagnostics by the Polymerase Chain Reaction (PCR) has rapidly become an invaluable technique for the detection, molecular characterisation and clinical management of a wide variety of Haematological disorders. Within the Haematology laboratory, PCR is widely used for the identification of Leukaemia and Lymphoma associated genetic abnormalities. The hallmark in the diagnosis of certain Leukaemias, such as Chronic Myeloid Leukaemia and Acute Promyelocytic Leukaemia, is the identification of specific chromosomal translocations.
Blood products: from Donor to Recipient
Transfusion medicine is the process of collecting, processing, testing, storing, and transfusing blood and blood products. This is a vital process in any hospital since many patients are dependent on the availability of blood components either after an operation or else to maintain adequate blood parameters (such as haemoglobin and platelets) which can be affected from treatment such as chemotherapy and radiotherapy.
Biomedical scientists are responsible in processing donated blood to produce various components such as red cell concentrate, plasma and platelets. Scientists perform rigorous testing to check the quality of these blood products before being transfused to the patient. Quality tests include screening for unexpected red cell antibodies, transmissible infectious diseases such as hepatitis and HIV, and bacterial contamination of platelets. Other tests are also performed before the product is transfused to the patient to ensure that the product is compatible with the patient. The aim of the transfusion lab and blood bank is to ensure that the patient is provided with a blood product which is safe.
Well being of the general public and the environment
Public Health Laboratories
The role of public health sector is to promote and protect the well being of communities and their environments by preventing disease outbreaks, ill health and injury. Medical scientists working in the public health laboratories are often responsible in testing the quality of food and environmental samples by conducting microbiological and chemical tests on samples like sea water and food which is to be consumed by the general public. These tests will identify the presence of any bacterial contamination which could lead to food poisoning if ingested or the presence of high levels of toxic chemicals in food or water.
The science behind the building blocks of biological life
Genetics plays a central role within the Department of Pathology, whereby it conducts a number of tests (molecular and cellular) in order to characterise the mechanisms and biological relevance of the DNA variants and Chromosomal aberrations and their role in disease. Clinical genetic testing refers to the laboratory analysis of DNA or RNA to assist in the diagnosis of disease. Genetic testing can provide definitive diagnosis or it may help the medical professional in predicting the likelihood of inheritance or developing a particular disease before symptoms even appear.
The main biological samples of choice that are received and processed in the laboratory include peripheral blood in an anticoagulant solution, mouthwash specimens, and human tissue samples. Genetic testing is useful in identifying 1) single gene disorders (Thalassaemia, Sickle Cell Disease, Cystic Fibrosis, bleeding disorders, and other haematological conditions), 2) complex and multifactorial disorders (Duchenne Muscular Dystrophy, Breast and Colon Cancer)
Molecular Diagnostics - Infectious Diseases
Molecular Diagnostics is a rapidly growing multi-disciplinary science. The largest area, where demand is increasing at an alarming rate, is the diagnosis of infectious diseases. Identification of pathogens is carried out by using molecular methods such as real-time PCR, reverse hybridisation and Next Generation Sequencing. The laboratory specialises in the identification of respiratory pathogens, HPV, enteric bacteria, viral/bacterial meningitis and Mycobacteria, to mention a few. It also plays a role in monitoring viral loads and genotyping/resistance testing of chronic infections such as HCV and HIV. The molecular diagnostics has now also expanded into metagenomics i.e. the genomic analysis of micro-organisms.
A diagnostic branch of medicine involving the study of human cells, tissues and organs
The Cytology laboratory is responsible for the examination of single cells shed from human tissues. Material from gynaecological and other body sites is obtained without the need for invasive surgery and examined microscopically to detect morphological changes, including the presence of inflammatory pre-malignant or malignant cells.
Cytology specimens from a patient are smeared onto a slide and stained. The prepared slides are then examined under the microscope by the biomedical scientists and surgical pathologists to look at the number of cells on the slide, what types of cells they are, how they are grouped together, and what the cell details are (shape, size, nucleus etc). This information is useful in determining whether a disease is present and what is the likely diagnosis.
Cytological analysis proves to be a very useful screening tool; to look for disease and to decide whether or not more histological tests need to be performed.
The mortuary is responsible of carrying out autopsies on deceased individuals and prepare them for burial. Autopsies are significant to determine the cause of death in cases when patients die of an unknown cause, or a forensic investigation is requested by the police and judicial system.
The Histology laboratory deals primarily with the diagnosis of benign and malignant conditions based on the microscopic analysis of tissue samples, ranging from biopsies (as may be obtained during an endoscopic procedure or following radiologically-guided tissue sampling) to major surgical resections. In cases of malignancy, prognostically-relevant information can be relayed to the oncological team, in particular, tumour staging, which has a significant impact on patient management post operatively.
Biomedical scientists work alongside histopathologists to macroscopically assess specimens and to take the necessary tissue samples. After gross examination, tissue processing, embedding and cutting, tissues are stained using various dyes so as to assess cellular detail and tissue architecture at the microscopic levels to render a diagnosis.
Immunohistochemistry forms one of the cornerstones of diagnostic Histopathology. Through the use of antibodies targeted against specific tissue antigens that may be over- or underexpressed in disease, diagnostic accuracy is markedly improved. Furthermore, novel antibodies are currently in use, which have significant therapeutic and prognostic implications and which may unmask an underlying genetic basis for disease.
Investigations of chemical and biochemical components in body fluids
Clinical Biochemistry involves the measurement of the concentration (or level) of various chemical components in body fluids, most commonly in blood or urine samples. The components measured in the Clinical Chemistry Laboratory include: blood glucose, lipids, proteins and enzymes, hormones, electrolytes and metabolic products, and tumour markers.
These chemical components are measured with the use of specialised automated instruments or manual techniques, most of which are based on the use of photometric or immunoassay reactions.
The aforementioned assays are essential for the diagnosis of metabolic diseases, monitoring of disease progression and the efficacy of drug therapy. The clinical chemistry laboratory is also involved in screening programs, including those for colorectal cancer and newborn screening for congenital hypothyroidism, and in the assessment of male fertility as part of the work up prior to in-vitro fertilisation (IVF).
Immunology is the study of the immune system. The immune system uses various mechanisms to protect our body from infections. One of these mechanisms is the production of antibodies in response to the presence of a foreign organism or substance. Low levels of antibodies result in low immunity which increases the possibility of infections, however an uncontrolled production of antibodies may lead to autoimmune disease. Clinical Laboratory Immunology is the study of these autoimmune diseases and through the use of various specialized tests is able to diagnose conditions such as rheumatoid arthritis, SLE (lupus), Crohn’s and coeliac disease. The Biomedical Scientists working in this field use techniques like fluorescence microscopy to identify the presence of these autoantibodies.
Study of pathogenic microorganisms causing human infections
The Clinical Virology Laboratory specialises in the identification of human viruses such as HIV and Hepatitis A/B/C.
Identification of viruses is carried out by serological tests which detect specific antibodies against a virus, immunoassays which detect viral proteins and cell culture techniques .
Parasites are identified according to their ova and cysts by means of direct microscopical examination and staining of faeces and urine.
The Clinical Bacteriology laboratory has a significant role in the culture and sensitivity testing of pathogenic bacteria.
Biomedical Scientists culture pathogens from an array of different specimens such as pus, faeces, urine, sputum, blood, and CSF to name a few. Pathogenic bacteria are first isolated on different and selective culture media. Bacteria may be identified up to species level on the basis of growth characteristics, microscopical morphology, metabolic and biochemical tests, and reactivity with specific antibodies.
Determining antibiotic sensitivity of the pathogen to different drugs is of utmost importance when deciding patient treatment and management, even more so in recent years where antibiotic resistance is on the rise.
The Clinical Mycology Lab specialises in the study and isolation of fungi causing infections, including the dermatophytes, opportunistic fungi (significant in patients who are immunosupressed) and the true pathogenic fungi.
Diagnosis of fungal infections requires direct microscopy on various samples, culturing of the organism on selective plates, together with microscopic examination of moulds or identification of yeasts. Sensitivity testing is also carried out to aid clinicians to prescribe the appropriate antifungal treatment.