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Tests
A free light chains test measures the level of free light chains in your blood. Light chains are proteins made by plasma cells, a type of white blood cell. Light chains usually link up with other proteins called heavy chains. Together, the light and heavy chains make immunoglobulins, also called antibodies. Antibodies are proteins that your immune system makes to fight germs such as viruses and bacteria .
Indicators
Qualitative or quantitative marker of active hepatitis C infection.
Tests
Confirms active hepatitis C infection and verifies cure after treatment.
Tests
An HIV test checks a sample of your blood, saliva (spit), or urine (pee) to see whether you are infected with HIV (human immunodeficiency virus). HIV is a virus that destroys certain cells in your immune system . These cells protect your body against diseases from germs , such as bacteria, viruses, and fungi. If you lose too many immune cells, your body will have trouble fighting off infections and other diseases.
Indicators
Along with the immunoglobulin G4 subclass (IgG4), the IgG3 subtype makes up a minor part of circulating antibodies in healthy individuals. The core hinge sequence contains approximately four times the number of amino acids as the other subclasses; allotypes of IgG3 can have up to 62 hinge residues and up to four interchain disulfide bonds. The increased hinge size for IgG3 increases the separation between the Fc (constant fragment) tail and Fab (antigen binding fragment) arms of antibodies of this subclass. This enhances the relative flexibility of the molecule, which may modulate antigen-binding capacity and immune complex formation, and may increase the affinity for binding to both Fc receptors and complement component C1q.
Indicators
Along with the immunoglobulin G3 subclass (IgG3), the IgG4 subtype makes up a minor part of circulating antibodies in healthy individuals. The IgG4 core hinge sequence contains 12 amino acids and two interchain disulfide bonds.This subtype has moderate affinity for binding Fc receptors and does not bind complement component C1q. The production of IgG4 can be stimulated following repeated or long-term exposure to antigen. Elevated levels are found in various diseases and infections and can be indicative of an fibroinflammatory syndrome known as IgG4-related disease.
Tests
An immunoglobulins blood test measures the amount of immunoglobulins in your blood. Immunoglobulins are also called antibodies. Antibodies are proteins that your immune system makes to fight germs , such as viruses and bacteria . Your body makes different kinds of antibodies to fight germs in different parts of the body and at different stages of an infection.
Tests
Laboratory test involving interaction of antigens with specific antibodies.
Article
Research record from Clin Chim Acta, 2026-05-15. PMID 42142695.
Tests
Lyme disease is an infection caused by bacteria you get from tick bites . Lyme disease tests look for signs of infection in a sample of your blood or cerebrospinal fluid (CSF). CSF is a clear liquid that flows in and around your brain and spinal cord. The test checks your sample for antibodies that your immune system makes to fight the bacteria that cause Lyme disease.
Tests
A proprietary serology assay that can be used to measure IgG antibodies against the SARS-CoV-2 nucleocapsid protein (N).
Tests
A proprietary serology assay that can be used to measure IgM antibodies against the SARS-CoV-2 nucleocapsid protein (N).
