The hepatitis-B vaccine has been produced on a large scale through

Options

A. Recombinant DNA technology using Claviceps
B. Recombinant DNA technology using E. coli
C. Recombinant DNA technology using yeast
D. Recombinant DNA technology using mice

Answer

To solve the question regarding the production of the hepatitis-B vaccine on a large scale, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the method used for the large-scale production of the hepatitis B vaccine.

2. **Identifying the Technology**: The hepatitis B vaccine is produced using recombinant DNA technology (RDT). This technology allows for the manipulation of genetic material to produce desired proteins or vaccines.

3. **Role of Vectors and Hosts**: In recombinant DNA technology, a gene that codes for the hepatitis B surface antigen is inserted into a vector (a DNA molecule used to deliver genetic material into cells). This vector is then introduced into a host organism.

4. **Choosing the Host**: The host organism used for the production of the hepatitis B vaccine is typically yeast. Yeast is favored because it can grow rapidly and produce large quantities of the desired protein.

5. **Cultivation in Bioreactors**: The genetically modified yeast is cultivated in bioreactors under optimal conditions (temperature, pH, nutrients) to maximize the production of the hepatitis B surface antigen.

6. **Final Product**: After sufficient growth and protein expression, the hepatitis B surface antigen is harvested and purified to create the vaccine.

7. **Conclusion**: Based on the above steps, the correct answer to the question is that the hepatitis B vaccine has been produced on a large scale through recombinant DNA technology using yeast.

### Final Answer:
The hepatitis-B vaccine has been produced on a large scale through recombinant DNA technology using yeast.

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