An antibody is an immunoglobuin protein capable of binding with an antigen.
Antibodies are against bacteria.
To see an antibody you would have to magnify it 1,450,000 times. There are 5 different kinds of antibodies. The IgA is found mainly in the mucous membranes, where it intercepts antigens in the nose and throat. IgE binds to certain antigens to cause allergic reactions. The largest antibodies, IgM and IgG, the most common , play the major role in attacking many bacteria and and other antigens.