Laboratory Analysis of the Immune Response

What are monoclonal antibodies?

Made from one B cell and bind to one specific antigen; very specific

What are polyclonal antibodies?

Made from many B cells and bind to multiple parts of an antigen; less specific

What is the main difference between monoclonal and polyclonal antibodies?

Monoclonal are specific to one antigen while polyclonal are broad and bind multiple

What is antibody cross-reactivity?

When an antibody binds to the wrong antigen

Why do monoclonal antibodies have less cross-reactivity?

They bind to only one specific epitope

What is the purpose of assays?

To detect antigen-antibody reactions

What are common types of assays?

ELISA, agglutination, precipitation, and Western blot

What is a precipitation reaction?

When antigen and antibody form a visible solid

When does precipitation work best?

When antigen and antibody are in equal optimal amounts

How are antibodies used to diagnose disease?

Their presence shows past or current infection

What is direct agglutination?

Clumping occurs because antigens are naturally on cell surfaces

What is indirect agglutination?

Antigens are attached to beads to detect smaller molecules

What is hemagglutination?

Clumping of red blood cells

What is hemagglutination used for?

Blood typing, virus detection, and measuring antibodies

How are blood types determined?

By identifying A, B, and Rh antigens on red blood cells

What is cross-matching blood?

Mixing donor and recipient blood to check for clumping

What does no clumping in cross-matching mean?

The blood is compatible and safe

What is ELISA?

An enzyme-based test that shows results with a color change

What is EIA?

A general term for enzyme-based tests including ELISA

What is FEIA?

An enzyme test that uses fluorescence instead of color

What is immunohistochemistry?

A method to detect proteins in tissue samples

What is immunocytochemistry?

A method to detect proteins in individual cells

What does direct ELISA detect?

Antigens

What does indirect ELISA detect?

Antibodies

What is a benefit of immunofluorescent assays?

They glow, making results easier to see and more sensitive

What is a direct fluorescent antibody test?

A labeled antibody binds directly to an antigen

What is an indirect fluorescent antibody test?

A secondary labeled antibody binds and increases signal strength

What is flow cytometry?

A technique that uses lasers to count and identify cells

What is FACS?

A technique that sorts and separates specific cells from a mixture