Serology

cell free fraction of blood

classification of blood types

Serology is the scientific study of antibodies in the serum and other body fluids. Such antibodies are typically formed in response to an infection (against a given microorganism), against other foreign proteins (in response, for example, to a mismatched blood transfusion), or to one's own proteins (in instances of autoimmune disease).

thumb|right|300px|Two serotypes 1a and 1b with antigens 2a and 2b on surface, which are recognized by two distinct [[antibodies, 3a and 3b, respectively]]

thumb|right|The general stages of seroconversion for hepatitis B, where the line of detectability indicates seropositivity In immunology, seroconversion is the development of specific antibodies in the blood serum as a result of infection or immunization, including vaccination. During infection or immunization, antigens enter the blood, and the immune system begins to produce antibodies in response. Before seroconversion, the antigen itself may or may not be detectable, but the antibody is absent. During seroconversion, the antibody is present but not yet detectable. After seroconversion, the

in medicine, the time between first infection and detectability

Seroprevalence is the number of persons in a population who test positive for a specific disease based on serology (blood serum) specimens, often presented as a percent of the total specimens tested or as a proportion per 100,000 persons tested. As positively identifying the occurrence of disease is usually based upon the presence of antibodies for that disease (especially with viral infections such as herpes simplex, HIV, and SARS-CoV-2), this number is not significant if the specificity of the antibody is low.

laboratory test

Use of Sodium by organisms

test for source species of blood

A serodiscordant relationship, also known as mixed-status, is one where one partner is infected by HIV and the other is not. This contrasts with seroconcordant relationships, in which both partners are of the same HIV status. Without effective prevention measures, serodiscordant relationships can significantly contribute to the spread of HIV/AIDS, with the risk varying based on the type and frequency of sexual activity and the viral load of the HIV-positive partner.

Serostatus refers to the presence or absence of a serological marker in the blood. The presence of detectable levels of a specific marker within the serum is considered seropositivity, while the absence of such levels is considered seronegativity.