The most modern technique of vaccine preparation is

Options

A. Extraction of antigens from pathogens
B. Multiplication of antigens through rDNA
C. Weakening of pathogen through chemical treatment
D. Attenuation of pathogen through heat

Answer

To answer the question about the most modern technique of vaccine preparation, we can break down the options and analyze them step by step:

### Step-by-Step Solution:

1. **Understanding Vaccination**:
- Vaccination is a process that helps to make a person immune or resistant to an infection. This is achieved through the administration of vaccines.

2. **Types of Vaccines**:
- Vaccines can be made from killed microorganisms, living attenuated microbes, or living virulent organisms. Each type has its own method of preparation.

3. **Analyzing the Options**:
- **Extraction of Antigen from Pathogen**: This method involves isolating specific antigens from pathogens but is not the most modern technique.
- **Multiplication of Antigen through rDNA**: This refers to recombinant DNA technology, where DNA from a pathogen is inserted into another organism to produce antigens. This is a cutting-edge approach in vaccine development.
- **Weakening of Pathogen through Chemical Treatment**: This method involves altering the pathogen to make it less virulent, but it is not as advanced as rDNA technology.
- **Attenuation of Pathogen through Heat**: This traditional method involves using heat to weaken pathogens, which is also not the most modern technique.

4. **Conclusion**:
- Based on the analysis, the most modern technique of vaccine preparation is the **multiplication of antigen through recombinant DNA technology (rDNA)**. This method allows for the production of specific antigens in a controlled manner, leading to more effective vaccines.

### Final Answer:
The most modern technique of vaccine preparation is **multiplication of antigen through recombinant DNA technology (rDNA)**.

---