(iii) therapy in humans and animals and

(iv) industrial applications like immunopurification.

Ten to twenty years ago, antibodies were available in milligram amounts, today due to increasing demand, antibodies are needed in multi kilograms per year.

Two approaches have been followed for the production of monoclonal antibodies:

(i) in vivo production using ascites tumours in mice or rats,

(ii) in vitro production through cell culture technique.

The second method is economically viable in view of the increasing demand. It has following additional advantages:

(i) it can be scaled up; for instance, one kilogram of antibody (which can be produced through cultured cells in a single fermenter), would require 20,000 mice, if made by ascites tumours;

(ii) the risk of contamination is greatly reduced.