This chapter provides an overview of biomedical science and the role of biomedical scientists. Biomedical science is often described as the application of the basic sciences, but especially the biological sciences, to the study of medicine, in particular, the causes, consequences, diagnosis, and treatment of human diseases. The title of biomedical scientist is a protected one and biomedical scientists are registered practitioners of the subject. They normally work in departments of clinical pathology. Thus, they are vital healthcare, scientifically qualified professionals who, for example, perform diagnostic tests on clinical samples of blood and urine. Given their role(s), biomedical scientists are typically active in laboratory-based work and tend to have a relatively limited contact with patients compared with other healthcare professionals.
Biomedical science and biomedical scientists
Edited by Nessar Ahmed, Hedley Glencross, and Qiuyu Wang
The Fundamentals of Biomedical Science looks at the challenges of practicing biomedical science. Biomedical scientists are the foundation of modern healthcare, from cancer screening to diagnosing HIV, from blood transfusion for surgery to food poisoning and infection control. Without biomedical scientists, the diagnosis of disease, the evaluation of the effectiveness of treatment, and research into the causes and cures of disease would not be possible. The text draws together essential basic science with insights into laboratory practice to show how an understanding of the biology of disease is coupled to the analytical approaches that lead to diagnosis.
Qiuyu Wang, Nessar Ahmed, and Chris Smith
This chapter explores centrifugation, which is the mechanical process of separating mixtures by applying centrifugal forces. It is one of the most widely used techniques in biochemistry, molecular and cellular biology, and in the biomedical sciences. The chapter begins by explaining the basics of centrifugation theory. Centrifugation is a separation technique conducted in an instrument called a centrifuge. A centrifuge holds a spinning rotor containing samples in tubes that are rotated around a central axis by a motor. This spinning of the rotor generates a centrifugal force that separates the components in the mixture on the bases of differences in size and/or density. The major centrifugation techniques used are differential and density gradient centrifugation. When using centrifuges, all appropriate safety considerations must be observed.
Qiuyu Wang, Nessar Ahmed, and Chris Smith
This chapter studies chromatography, which is the collective term for a family of analytical techniques used to separate the components of mixtures of molecules for their identification and possible estimation of their concentrations in the original mixture. All chromatographic techniques are based on differences in the relative affinities of the molecules in a mixture of two different and immiscible phases, one of which is mobile and the other stationary. The basis of all forms of chromatography is the partition or distribution coefficient, which describes the way in which a substance distributes at equilibrium between two immiscible phases. Most types of chromatography are used in biomedical science laboratories to assist in analysing and purifying analytes from a variety of clinical samples. The chapter then looks at planar chromatography, column chromatography, high-performance liquid chromatography, and gas-liquid chromatography.
Communications in laboratory medicine
Hedley Glencross and Georgina Lavender
This chapter highlights the importance of adequate communication skills within the clinical laboratory and how communications by laboratory personnel can affect the perceptions of users of the service they provide. Effective communication within a clinical laboratory, between its staff and a variety of external people and organizations, is necessary. This is because biomedical scientists who work as part of a laboratory team, must follow local policy and procedures, and comply with legislation, and are involved in a process that provides essential information contributing to patient care. Indeed, biomedical scientists must conform to current legislation, such as the Data Protection, Freedom of Information, and Human Tissue Acts, and be aware of the consequences of their actions if inappropriate records are kept and audit trails are not maintained. Biomedical scientists must also ensure that all work carried out within laboratory medicine has appropriate consent and that confidentiality is always maintained.
This chapter assesses electrochemistry, which is the study of the chemical changes produced by electrical currents and also the production of electrical currents by chemical reactions. All electrochemical techniques involve the use of two electrodes and the measurement of the potential difference between them (potentiometry) or the current that flows between them (voltammetry). Potentiometry involves the generation of a spontaneous potential that is measured against that produced by a reference electrode as a potential difference. In voltammetric techniques, electrochemical reactions are not spontaneous, but are forced to occur by an imposed external voltage. The chapter then outlines the likely uses of electrode devices within a clinical laboratory and describes their fundamental principles of operation. It also looks at biosensors, which are widely used in the analysis of glucose concentrations for the diagnosis and management of diabetes.
Qiuyu Wang, Nessar Ahmed, and Chris Smith
This chapter discusses electrophoresis, which is the movement of charged molecules or ions in an electric field. Ions that differ in their charge and/or mass will move at different rates such that if they have a common starting point they will separate over time as some will move faster than others. As a result, the components of a mixture will be separated. Thus, electrophoresis is a separation technique. However, it can also be adapted to provide analytical data, such as the size of molecules. Electrophoresis has many applications in the biomedical sciences: in separating proteins and nucleic acids, in assessing purity of biological samples, and in estimating the sizes of molecules. The chapter then describes the uses of the major types of electrophoretic separation techniques. It also explains the underlying principles of isoelectric focusing, before considering the uses of pulsed field and two-dimensional gel electrophoresis.
Fitness to practise
This chapter discusses the Health and Care Professions Council (HCPC) and the Institute of Biomedical Science (IBMS). It considers how their respective, but complementary, approaches to fitness to practise differ, and explores their contributions to the training and career development of biomedical scientists. The work of the HCPC is designed to safeguard the public from being harmed by the actions or inactions of healthcare professionals. To remain on the HCPC register, an individual registrant is required to sign a personal declaration every two years confirming that they continue to meet the HCPC Standards of Conduct, Performance and Ethics, and their Standards of Proficiency. Meanwhile, the IBMS or the Institute is the professional body for biomedical scientists in the UK. It promotes and develops biomedical science and those who practise biomedical science, and is therefore principally concerned with professional matters and issues related to its members.
Health and safety
Hedley Glencross and Alison Taylor
This chapter examines the legal requirements and regulations governing occupational health and safety, including the methods used to assess and control risks. It focuses on the risks and controls particular to biomedical science laboratories. The Health and Safety at Work Act (HASAWA) and the Management of Health and Safety at Work Regulations form the legal framework that ensures the safety of everyone in the workplace. Risk assessment is the primary tool prescribed in legislation to ensure high standards of health and safety. Risk assessments identify hazards and those who are potentially in danger; they evaluate the risks associated with those hazards and suggest how the risks can be reduced to acceptable levels. Ultimately, ensuring a high standard of health and safety in the workplace is desirable because the overt costs associated with incidents and injuries are considerable.
Christine Yates and Qiuyu Wang
This chapter begins by outlining the principles of the immune system and the fundamentals of immunoassay, which are essential to the understanding of routine immunological diagnostic assays. Immunological techniques largely depend upon the visualization of antibody–antigen reactions, detecting the formation of immune complexes or the attachment of labelled antibodies to cells or an artificial surface by a variety of methods. A range of immunological techniques have been developed to detect and measure the concentrations of cellular and humoral elements of the immune system in health and disease and, in some cases, assess their biological activities. They have also been used to raise antibodies to other analytes, such as hormones and tumour markers, increasing the range of immunoassays available to biomedical scientists. The chapter then looks at the uses of polyclonal and monoclonal antibodies in the clinical laboratory.
This chapter evaluates laboratory automation, which is a multi-disciplinary strategy to research, develop, optimize and capitalize on technologies in the laboratory that enable new and improved processes and products. All clinical laboratories utilize automation albeit to a variable extent, dependent on the discipline and requirements of the service. The application of this automation has produced improvements in efficiency and effectiveness of testing and improved consistency of analysis. Pre- and post-analytical processes such as centrifugation, decapping, and recapping of specimen tubes, aliquoting, archiving, and storage of samples can be integrated into a single automated process by using tracking systems. Ultimately, automation is prevalent well beyond the highly automated biomedical science areas, and many microbiology, histology, cytology, and blood transfusion laboratories have a range of automated instrumentation.
Tony Sims and Qiuyu Wang
This chapter focuses on microscopy, which is the use of a microscope to examine and analyse objects that would normally be too small to be seen with the naked eye. Microscopes that use a single lens are called simple microscopes; those with more than one are compound microscopes. Microscopes are perhaps the most widely used instruments in biomedical science. They have contributed greatly to the knowledge and understanding of pathological processes, and are used in all branches of biomedical science. Light microscopes are used to look at cells and tissues. The electron microscope, with its vastly increased magnification and resolution, is used to visualize virus particles, explore the structures of bacteria, and observe more fully the subcellular components seen in both normal and diseased cells and tissues. The chapter describes how the various types of microscope are constructed and work, and how they can be applied to diagnostic biomedical practice.
Molecular biology techniques
Qiuyu Wang, Nessar Ahmed, and Chris Smith
This chapter examines molecular biology, which is generally concerned with the structures, functions, and interactions of the two major groups of macromolecules, the nucleic acids DNA and RNA, and proteins. Nucleic acids can be purified from organisms using a variety of techniques. Restriction endonucleases (REs) can digest the isolated DNA into smaller-sized fragments suitable for analysis and for use in a number of techniques of clinical interest. Molecular biology techniques are used in biomedical science and they rely on the complementary binding of nucleic acids to provide a convenient way of recognizing and isolating specific base sequences within fragments of DNA or RNA molecules include the sequencing of isolated DNA, Southern and Northern blotting, fluorescence in situ hybridization (FISH), the cloning of DNA by recombination and polymerase chain reaction (PCR) technologies, and DNA microarray analysis. The chapter then looks at CRISPR–Cas9, which is a quick and efficient method for editing genes.
Hedley Glencross and Georgina Lavender
This chapter looks at the personal and professional development of biomedical scientists. We are all aware that science is constantly evolving, and that today's innovations and discoveries are often old news and outdated by tomorrow. Anybody listed on a professional register is required to reaffirm and review continually their knowledge base within their chosen profession; biomedical scientists are no exception. Indeed, biomedical scientists are expected to be able to demonstrate a designated level of continuing professional development (CPD) to remain on the Health and Care Professions Council (HCPC) register. Moreover, every two years at the renewal of their registration, they must declare that they have been undertaking CPD to a predefined standard and, crucially, must be able to provide evidence to support this claim, if required.
Jan Still, Lynda Petley, and Garry McDowell
This chapter focuses on point-of-care testing (POCT), which is the provision of a diagnostic pathology testing service outside the traditional clinical laboratory setting and physically closer to the patient. This type of testing may be carried out by healthcare professionals in the ward, clinic, or general practitioner (GP) surgery; by high street pharmacists; or by the patients themselves. Modern POCT now consists of a variety of devices from simple hand-held meters and test kits to more sophisticated portable and bench top analysers. The chapter then introduces the basic concept of rapid testing. It illustrates how POCT is governed and regulated, describing the requirements for a well-managed, reliable POCT service, and how such a service can be established and maintained. The chapter also discusses the training and competence of POCT practitioners, and highlights the dangers associated with a lack of or poor-quality training.
Preparing and measuring reagents
This chapter details the process of preparing and measuring reagents, which are essential and fundamental skills for all biomedical scientists. The use of balances for weighing and pipettors and other volume measurement methods for volume delivery are key techniques in the production of solutions and their dilution. For correct operation, balances must be appropriately sited and calibrated. Burettes, pipettes, and volumetric flasks provide high levels of accuracy if used correctly. However, pipettors are the volume measurement tool of choice for highly accurate and precise work. They use disposable tips for convenience, require calibration, and, being precision instruments, must be used with care. The chapter then looks at molar concentrations and alternative ways of expressing concentration.
Quality assurance and management
This chapter assesses quality assurance and management in clinical laboratories. The necessity to provide services of appropriate quality in medical laboratories, as well as the need to satisfy the users of laboratory services, has led to increasing numbers of regulations governing their operations and assessment. Indeed, medical laboratories are subjected to inspection and assessment by a number of different bodies, namely the United Kingdom Accreditation Service (UKAS), the Human Tissue Act (HTA), the Medicines and Healthcare products Regulatory Agency (MHRA), and the Care Quality Commission (CQC). A variety of techniques, such as audit, can be used by the laboratory to assess internally their compliance to set standards. Ultimately, following good laboratory practices ensures the integrity of the sample audit trail in the laboratory and allows the cycle of continual improvement to be embedded into the laboratory culture.
Samples and sample collection
This chapter describes the range of samples and the procedures for their collection. Blood and other tissues, and body fluids can be tested in clinical laboratories to aid in preventing, diagnosing, and treating diseases and disorders. A variety of analytical techniques are used, which are being continually developed and improved in terms of accuracy and ease of use by biomedical scientists. Samples for clinical testing include whole blood, plasma, serum, urine, and faeces for chemical and cellular analyses; tissues and curettings, which are scrapings of tissues, for histological examination to identify pathological changes; and swabs may be taken from various parts of the body for microbiological culture. The quality assurance in obtaining samples for testing by clinical laboratories includes correctly identifying patients, obtaining samples using correct procedures, meticulous labelling of samples and request forms, adhering to health and safety procedures, and being aware of standard operating procedures (SOP) for sample processing.
Qiuyu Wang, Helen Montgomery, Nessar Ahmed, and Chris Smith
This chapter addresses spectroscopy, which is concerned with the interactions of electromagnetic radiation and matter, particularly the absorption of radiation by matter and, in some cases, its emission, and can be used to quantify molecules of interest in biomedical laboratories. Many molecules absorb light of characteristic wavelengths in the visible, UV, or IR regions of the electromagnetic spectrum. This is used as the basis for determining their concentrations using spectrophotometers and colorimeters. The absorbance of light of a specific wavelength by a solution of biological molecules depends on their concentration and the distance travelled by the light through the solution, as described by the Beer–Lambert law. The chapter then looks at infrared (IR) and Raman spectroscopy, light-scattering methods, fluorimetry, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry.