Biochemical Assay in Clinical Diagnostics: What You Need to Know

What is Biochemical Analysis?

Biochemical analysis refers to the study of chemical processes within living organisms, focusing on their structure, composition, and related biochemical reactions. It helps identify and quantify cellular processes and metabolic reactions, providing insight into the function of diverse biomolecules, e.g., proteins, carbohydrates, lipids, enzymes, and nucleic acids in biological samples, such as blood, saliva, urine, and tissues. Thus, biochemical analysis helps to understand the buildup and breakdown of biomolecules. It also helps to distinguish between different species of microorganisms, diagnose diseases, and monitor therapeutic outcomes and long-term maintenance. For example, biochemical tests help to monitor diabetes and hyperlipidemia by detecting and quantifying specific biomolecules in blood.

Different Types of Biochemical Assays

Biochemical Assays are laboratory procedures used to detect, quantify, and study the activity or binding of biomolecules, mostly under in vitro conditions. Broadly, biochemical assays can be enzymatic assays, receptor binding assays, cell-based assays, immunoassays, nucleic acid assays, functional assays, and other specialized assays. Enzymatic assays (such as enzyme kinetics assays, kinase assays, protease assays, etc.) measure the activity of enzymes that catalyze biochemical reactions. Receptor binding assays evaluate the binding affinity of ligands for their targets. Cell-based assays (such as cell viability assays and angiogenesis assays) measure the activity/response of biological molecules within cells. Immunoassays (such as ELISA and Western Blot) help to detect and quantify proteins or other molecules, while nucleic acid assays detect and quantify nucleic acids, commonly using polymerase chain reactions. Lastly, functional assays, such as cytokine release assays and chemotaxis assays, study the function of a biomolecule or pathway.

Applications of Biochemical Assay in Clinical Diagnostics

Biochemical assays serve as essential tools in clinical diagnostics. They detect diseases, monitor therapeutic outcomes, and assess organ functioning. In terms of disease diagnosis, biochemical assays can detect the presence of antibodies or chemicals that are indicative of a disease. For treatment monitoring, biochemical assays utilize specific molecules known as biomarkers that indicate disease and its severity or help in its staging. These biomarkers are detected in samples such as blood, urine, cerebrospinal fluid, or other biological fluids. These assays also help determine the health and functioning of vital organs in the body, such as the liver, kidneys, heart, thyroid, and others, by detecting associated biomarkers or enzyme levels. These assays also help to assess cardiovascular risks and monitor diabetes by determining blood glucose levels.

Having understood that biochemical assays play an indispensable role in clinical diagnostics, let us look at some frequently used assays in clinics. For example, the liver is a vital organ that has a crucial role in maintaining overall health. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are transaminases primarily found in liver cells. Upon damage, liver cells release these enzymes into the bloodstream. Thus, elevated levels of ALT and AST detected using alanine aminotransferase (ALT) and aspartate aminotransferase (AST) assays reflect liver cell damage. In addition, total protein, albumin, and globulin assays provide a measure of these key proteins in the blood, thus helping clinicians to assess protein production and liver function.

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Diabetes is another health condition that affects a significant proportion of the population. It is projected that by 2050, one out of every eight adults will be affected by this condition. This stat makes it extremely important to monitor blood glucose levels in healthy and diabetic individuals. Fasting and postprandial blood glucose assays help ascertain blood glucose levels before and after eating meals. The HbA1c assay estimates the average blood glucose levels for the past 2 to 3 months. This assay determines the percentage of glycated hemoglobin containing red blood cells.

Kidney health is another vital aspect determining our overall health. The kidneys act as a filter, helping remove wastes and excess fluid from the blood, thereby regulating overall blood pressure. Thus, damage to renal cells can lead to various health problems. The creatinine assay is a simple biochemical test that allows the measurement of creatinine in a blood or urine sample. Since creatinine is a waste product that is eliminated from the blood by the kidneys, elevated levels of creatinine in blood or lower levels of creatinine in urine may indicate renal problems.

In addition to health and disease, biochemical assays help to determine the harmful effects of substances and chemicals on living organisms through a tox study or a toxicity study assay. The tox study is extremely important in drug development. It can assess the harmful effects of a drug candidate at an early stage and thus prevent delay or disruption in the drug development pipeline. These assays may be in vitro or in vivo, depending on the research goals, and some examples are the Ames test, the micronucleus assay, and the LD50 assay. In addition to their role in drug development processes, tox studies can determine the effect of chemicals and pollutants on the environment and the threats they pose to public health.

Thus, biochemical assays serve as an indispensable tool in clinical diagnostics, along with other disciplines such as drug discovery and development, molecular biology, environmental science, and basic research.