Blood serology is an aspect of the biological, medical, and forensic sciences that involves the study of blood serum, the liquid component of blood that does not contain blood cells or clotting factors. Blood serum contains many antibodies that can be analyzed for scientific, diagnostic, or forensic purposes. Antibodies have highly specific structures and are produced by the body to confront specific threats, so an analysis of the antibodies contained in a serum sample can often return valuable information about any infections or illnesses that an individual may have. Some aspects of blood serum are unique to each person, so serum analysis can also be used to connect an individual to a crime scene if forensic evidence is available. The term "blood serology" can be used to describe either the study of blood serum or the practice of analyzing serum for a particular purpose.
A blood serology test is generally quite simple and painless. A health professional draws a small amount of blood from a vein and collects it into a tube or vial. The blood is allowed to clot in order to remove clotting factors and the liquid serum is separated from the blood cells. The serum is then analyzed for antibody content. The presence of significant amounts of a given antibody may indicate the presence of an infection or disorder.
There are many other pieces of information that a blood serology test can be used to reveal. Blood serology can, for example, be used to determine an individual's blood type. It can also be used to diagnose several autoimmune conditions. The presence of antibodies that target an individual's proteins or foreign proteins may indicate an autoimmune disorder or a rejected blood transfusion. Immune deficiency problems in which an individual lacks certain necessary antibodies can also be detected through blood serology tests.
Blood serology is commonly used in forensic science, as a great deal of information can be gathered from a relatively small sample of blood. It is necessary to ensure that the blood sample is not contaminated in order to avoid inaccurate results. A forensic scientist can determine whether or not a blood sample came from a human, determine the gender of the individual who lost the blood, and prepare an antibody and protein profile of the blood. This profile can be checked against suspects or victims and may be used to link a suspect or victim to a specific crime scene or weapon.