Serology and ELISA Testing Notes

Serology and Immunology Fundamentals

  • Serology: Study of blood serum and the immune response to pathogens.
    • Immune system reacts to infections via antibodies (humoral immunity).
    • Antibodies types:
    • Immunoglobulin M (IgM)
    • Immunoglobulin G (IgG)
  • Primary immune response: Initial increase in antibodies.
  • Secondary response: Enhanced response primarily involving IgG and less IgM.

Basic Terminology

  • Antigen: Substances from foreign bodies triggering antibody production.
  • Antibody (Immunoglobins): Serum proteins produced in response to antigens.
  • Epitopes: Parts of antigens recognized by the immune system.

Serological Testing

  • Ag-Ab interactions are highly specific, occurring in vivo or in vitro.
  • Tests detect either the antigen or antibody present in samples.

Hemagglutination

  • Agglutination: Clumping of red blood cells due to antigen-antibody reaction.

Blood Typing Procedure

  • Involves adding anti-serum drops to synthetic blood samples on a slide.
  • Observe for agglutination to determine blood type.

Pregnancy Testing

  • Detects human chorionic gonadotropin (hCG) hormone produced during pregnancy.
    • Urine tests: Common home tests; high accuracy (99%).
    • Blood tests: Conducted in healthcare settings.
    • Ultrasounds: Confirm pregnancy.

ELISA Testing

  • ELISA: A laboratory technique for detecting antibodies, antigens in biological samples.
    • Used in diagnosing infections (e.g., HIV) and measuring hormones.
    • Immunoassays: Tests based on antigen-antibody interactions.
  • Examples of ELISA uses:
    • Identifying infections (bacterial/viral).
    • Autoimmune diseases observation (e.g., Type 1 diabetes).
    • Hormone level estimation.
    • Screening blood donations and detecting drug use.
  • Various types of ELISA: Direct, Indirect, Sandwich, and Competitive ELISA for different applications.