physioex 12

• serology: the study of antibodies and antigen-antibody interactions
• serum: an amber-coloured, protein-rich liquid which separates out when blood coagulates
• antigens are any small molecule that produce antibodies
• antigenic determinants or epitopes are locations that can bind to antibodies
• nonspecific binding: the binding of antibodies to a molecule that is not the target of the antibody
• negative control with a positive result is a false positive and vice versa; invalidates all results
• direct fluorescent antibody technique uses antibodies to directly detect presence of antigen; used for bacteria and viruses
• elementary body: infectious small cell type that is capable of attaching to host cell
• reticulate body: larger cell that divides actively once inside host cell "vegetative form"
• ELISA stands for Enzyme Linked Immunosorbent Assay
• in direct fluorescent antibody technique ten or more elementary bodies (green) w/in 5ml diameter is positive
• identity: antigens are identical via epitopes; precipitin forms an arc
• partial identity: similar or related epitopes; precipitin line is spur pointing towards more similar antigen well
• non-identity: unrelated epitopes; x precipitin line
• ELISA used to test for presence of antigen or antibody
• direct ELISA detects the antigen
• indirect ELISA detects the antibodies that are produced due to presence of and antigen
• seroconversion is needed with a positive indirect ELISA
• in direct ELISA if an antigen is present a sandwich of antibody, antigen and secondary antibody will form
• in indirect ELISA if an antigen is present it binds to primary antibody which then binds to secondary antibody; secondary antibody enzyme binds to constant region of primary antibody
• southern blotting identifies DNA, northern blotting identifies RNA and gel electrophoresis identifies proteins (western blotting)
• western blotting aka immunoblotting uses antibodies to detect proteins, similar to indirect ELISA
• difference between ELISA and western blotting is that ELISA uses mixture of antigens whereas western blotting has protein band that is specific to the antigen
• lyme disease and HIV use western blotting technique
• bands from a positive western blot are from antibodies binding to specific proteins and glycoproteins