Immunology is the branch of biomedical science that explores the structure and function of the immune system, a complex network of cells, tissues, and molecules that collaboratively work to defend the body against pathogens and maintain its overall health. The field of immunology encompasses the study of both innate and adaptive immune responses, aiming to understand the mechanisms by which the body recognizes and responds to foreign invaders.

The immune system serves as a sophisticated defense mechanism, distinguishing between self and non-self entities. Its primary goal is to protect the body from infectious agents, such as bacteria, viruses, fungi, and parasites, while also participating in the detection and elimination of abnormal or malfunctioning cells, including cancer cells.

Key components of the immune system include white blood cells, antibodies, cytokines, and various organs and tissues such as the thymus, spleen, and lymph nodes. The immune response involves a series of coordinated actions, beginning with the recognition of foreign substances, followed by the activation of immune cells, and ultimately leading to the elimination of the threat. Here are the important tests used in the immunology section.

  1. Enzyme-Linked Immunosorbent Assay (ELISA): Quantifies the concentration of antibodies or antigens in a sample. It is widely used in diagnosing infections, autoimmune diseases, and allergies.
  2. Western Blotting: Separates and identifies proteins, often used to confirm the presence of specific antibodies or antigens.
  3. Flow Cytometry: Analyzes the characteristics of cells in a fluid stream, providing information about cell surface markers, cell size, and granularity. It is used to quantify and characterize immune cells.
  4. Immunofluorescence (IF) Staining: Utilizes fluorescent dyes to visualize the presence and location of specific proteins or antibodies in cells or tissues.
  5. Radioimmunoassay (RIA): Measures the concentration of antigens or antibodies using radioactively labeled substances. It is particularly sensitive and is used in research and clinical settings.
  6. Complement Fixation Test (CFT): Measures the activity of the complement system, an essential component of the immune system.
  7. Immunohistochemistry (IHC): Detects and visualizes specific proteins in tissue sections. It is used to study the distribution of antigens in tissues.
  8. Lymphocyte Proliferation Assay: Measures the ability of lymphocytes to divide and proliferate in response to stimulation. It is often used in research and vaccine development.
  9. Immunoelectrophoresis: Separates and identifies proteins based on their electrophoretic mobility and immunoreactivity.
  10. Titer Test: Determines the concentration of antibodies in a serum sample, providing information about the strength of the immune response.
  11. Rapid Tests (e.g., Rapid HIV Test): Provide quick results for the presence of specific antibodies or antigens, often used in point-of-care settings.
  12. Autoantibody Testing: Identifies antibodies that target the body’s tissues, aiding in the diagnosis of autoimmune diseases.