Antibodi
caption: Tiap antibodi mengikat pada antigen spesifik.
caption: The secreted mammalian IgM has five Ig units. Each Ig unit (labeled 1) has two epitope binding Fab regions , so IgM is capable of binding up to 10 epitopes.
caption: Several immunoglobulin domains make up the two heavy chains (red and blue) and the two light chains (green and yellow) of an antibody. The immunoglobulin domains are composed of between 7 (for constant domains) and 9 (for variable domains) β-strands .