Antibodies
What is the relationship between antibodies, antigens and epitopes?
Antigens are foreign substances that stimulate the immune system to produce antibodies
Antibodies are composed of two identical heavy chains (red and blue) and two identical light chains (yellow and green)
Lymphocytes can generate millions of different antigen binding sites by DNA rearrangement and mutation – processes restricted to immune cells!!
Fab regions of antibodies bind specifically to epitopes on antigens
Monoclonal antibodies recognize a single, well-defined epitope
Comparison: polyclonal vs. monoclonal
Detection protocols often use a sequence of antibodies
Secondary antibodies amplify the signal
Western blot

Monoclonal antibodies recognize a single, well-defined epitope
produced by cultured hybridoma cells

hybridoma cells are formed by fusing antibody-secreting lymphocytes from an animal with myeloma cells

hybridoma cells can be maintained indefinitely in tissue culture

hybridoma cells secrete large amounts of antibody that can be harvested from the culture medium