Which of the following is true w.r.t. manufacture of genetically engineered insulin ?

Options

A. C-peptide must be removed during maturation of insulin. This was the main challenge for the production of insulin using rDNA techniques
B. Eli Lily company was the first one to produce Humulin on commercial scale
C. Chain A and chain B of insulin are held together by disulphide linkages
D. All of these

Answer

To determine which statement is true regarding the manufacture of genetically engineered insulin, we can analyze the options provided based on the information about insulin production through genetic engineering.

### Step-by-Step Solution:

1. **Understanding Insulin**:
- Insulin is a hormone produced by the beta cells in the pancreas, crucial for regulating blood glucose levels.

2. **Identifying the Options**:
- We need to evaluate the options provided regarding the manufacture of genetically engineered insulin.

3. **Evaluating Option 1**:
- "C-peptide must be removed during maturation of insulin."
- This statement is incorrect. While C-peptide is part of the proinsulin molecule and is cleaved off during the maturation process, it is not necessary to remove it during the manufacturing of insulin through genetic engineering.

4. **Evaluating Option 2**:
- "Illy Lilly Company was the first one to produce Humulin on a commercial scale."
- This statement is correct. Eli Lilly was indeed the first company to produce human insulin (Humulin) using recombinant DNA technology.

5. **Evaluating Option 3**:
- "Chain A and Chain B of insulin are held together by disulfide linkage."
- While this statement is true regarding the structure of insulin, it does not pertain directly to the manufacturing process of genetically engineered insulin.

6. **Evaluating Option 4**:
- "All of these."
- Since not all previous statements are true, this option is also incorrect.

7. **Conclusion**:
- The only true statement regarding the manufacture of genetically engineered insulin is that "Illy Lilly Company was the first one to produce Humulin on a commercial scale."

### Final Answer:
The correct statement regarding the manufacture of genetically engineered insulin is: **"Illy Lilly Company was the first one to produce Humulin on a commercial scale."**

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