Preformed antibodies need to be injected to treat the bite by a viper snake. It is also a type of immunization which is called as passive immunization. Antibodies, produced by B-cells, are typically made of basic structural units-each with two large heavy chains and two small light chains. B cells differentiate into plasma cells that secrete antibodies. Antibodies are proteins that bind to specific antigens and mark them for destruction by, for example, marking them more recognizable to phagocytic cells. Rejection of a kidney graft is not a function of B lymphocyte.