Blood serology is an aspect of biological, medical, and forensic science 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 tested for scientific, diagnostic, or forensic purposes. Antibodies have highly specific structures and are produced by the body to deal with specific threats, so an analysis of the antibodies contained in a serum sample can often return valuable information about any infection or disease an individual may have. Some aspects of blood serum are unique to each person, thus, 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 the study of blood serum or the practice of testing serum for a particular purpose.
A blood serology test is generally quite simple and painless. A healthcare professional draws a small amount of blood from a vein and collects it in a tube or vial. The blood is allowed to clot to remove clotting factors, and the liquid serum is separated from the blood cells. The serum is then tested for antibody content. The presence of significant amounts of a given antibody can 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 various autoimmune conditions. The presence of antibodies that target an individual's proteins or foreign proteins can indicate an autoimmune disorder or a rejected blood transfusion. Immunodeficiency problems in which an individual lacks certain necessary antibodies can also be detected by blood serology tests.
Blood serology is commonly used in forensic science, as a large amount of information can be collected from a relatively small sample of blood. It is necessary to ensure that the blood sample is not contaminated to avoid inaccurate results. A forensic scientist can determine whether or not a blood sample came from a human, determine the gender of the person who lost the blood, and prepare a blood protein and antibody profile. This profile can be verified against suspects or victims and can be used to link a suspect or victim to a specific crime scene or weapon.