Antibody/Antigen Interactions Flashcards
What is antigenicity?
the degree to which a molecule is able to bind to a B/T cell receptor or antibody
What is immunogenicity?
Degree to which an antibody is able to induce an adaptive immune response
Antigen can be antigenic but not immunogenic
What factors affect immunogenicity?
Size of the antigen - Larger is more immunogenic
The more complex the antigen = more immunogenic
Position on cell membrane
Chemical composition
What is a hapten?
Smaller molecule that is antigenic but not immunogenic unless bound to a larger molecule such as albumin
What is affinity?
Strength of single antigen/antibody bound
What is avidity?
binding strength of multivalent antigen
aVidity = multiValent
What is polyvalent?
Many antigenic sites on a single complex structure
What is polyclonal or polyspecific?
Multiple antibodies are produced against polyvalent antigen
What forces bind antibodies to antigens together?
Electrostatic or ionic bonds Hydrogen bonds Van der Waals forces hydrophobic bonds Also depends on fit = Lock and key All are weak bonds but combined they are strong
What is zeta potential?
Net negative charge on RBC membrane caused by sialic acid and NANA
Attracts positive ions and RBC’s repel each other
Ficin removes sialic acid and makes antigens accessible
What is prozone?
Too much antibody so only one antibody attaches and can form crosslinks
What is postzone?
Too much antigen. Every antibody binds to a seperate antigen and crosslinks can’t form
Polyrbene is a LISS-based method that when converted to AHG may have a false positive results due to
Complement bound to RBC membrane
