Now, what exactly is the purpose of these antibodies and what are these antibodies in the first place? Well, antibodies are specialized proteins. They are also known as immunoglobulins immune means immunity and globulants mean protein. So these antibodies circulate along our blood system and our lymph system until they basically bind to the specific antigen that is found on another pathogen or let's say, some type of bacterial cell. Now, once our antibody binds onto that antigen it can do two things. It can either call upon other leukocytes, for example, macrophages, to come and engulf that pathogen or it can begin to aggregate and form this very large insoluble complex in a process known as agglutination.