What is serology?

Serology is the study of blood serum, which is the clear liquid that separates from clotted blood, and it focuses on the immune responses present in the serum to diagnose diseases. This field of study is crucial because it allows for the detection of antibodies, antigens, and other components that are indicative of immune reactions, helping clinicians understand whether a person has been exposed to specific pathogens, such as viruses or bacteria. Serological tests are commonly used in various medical conditions, including infections, autoimmune diseases, and blood transfusion compatibility, making it a vital tool in modern diagnostics.

The other options refer to different areas of study within the broader fields of immunology and hematology, but only the first option accurately encompasses the essence of what serology entails.