What does serology examine in relation to blood?

Serology is a branch of diagnostic laboratory medicine that focuses on the study of blood serum and its components, especially antibodies. It plays a pivotal role in diagnosing infections, autoimmune diseases, and determining blood compatibility for transfusions. By examining the serum, which is the clear fluid that remains after blood has clotted, laboratory technologists can identify specific proteins, including antibodies that are produced in response to pathogens or foreign substances. This analysis is essential for understanding the immune status of an individual and can provide insights into recent infections or vaccinations, making it a crucial tool in both clinical and research settings.

The other choices do not accurately reflect what serology examines. Oxygen saturation levels pertain to respiratory function and oxygen transport in the blood, while blood glucose and lipid levels are assessed through biochemical tests rather than serological methods. The cellular content of blood, including red and white blood cells and platelets, is analyzed in hematology, separate from the serological examination of serum components.