A recombinant antigen is produced by cloning the gene encoding the antigen and expressing it in another organism.

A recombinant antigen is produced by cloning the gene encoding the antigen and expressing it in another organism.

• A. Derived from the pathogen's genome and expressed in another organism.
• B. Isolated directly from the pathogen without modification.
• C. Represents a whole inactivated pathogen.
• D. Is a non-protein carbohydrate.

Answer: (A)

Recombinant antigens come from cloning the gene that encodes the antigen and expressing that gene in a different, usually harmless, host organism. This means the antigen is derived from the pathogen’s genome and produced elsewhere in a laboratory system, rather than being taken directly as-is from the pathogen. It differs from an antigen obtained by isolating material directly from the pathogen, from a vaccine made from a whole inactivated pathogen, and from a non-protein carbohydrate antigen, which would be a different type of antigen product. The essence is using recombinant DNA technology to generate the specific protein antigen in a host organism.

Recombinant antigens come from cloning the gene that encodes the antigen and expressing that gene in a different, usually harmless, host organism. This means the antigen is derived from the pathogen’s genome and produced elsewhere in a laboratory system, rather than being taken directly as-is from the pathogen. It differs from an antigen obtained by isolating material directly from the pathogen, from a vaccine made from a whole inactivated pathogen, and from a non-protein carbohydrate antigen, which would be a different type of antigen product. The essence is using recombinant DNA technology to generate the specific protein antigen in a host organism.