At first the specific antigen was injected into a healthy mice and such antigen was made by the process of emulsification with Freund’s adjuvant or it was homogenized with a gel slice. Some other sources of immunogens can be intact cells, entire membranes, and even microorganisms are used times. It a common practice for the researchers to use mice in their respective labs in order to obtain their antibodies of interest. All it takes 14-21 days for the mice to be immunized which may fluctuate from researcher to researcher. When the time comes and the mice serum attains the optimum level of antibody titer, then the spleen is taken out and cells are collected which will be fused with myeloma cells.