The formula to calculate the number of copies of plasmid (P) is:
\[ P = \frac{I \times W_p}{W_i} \]
Where:
Let's say the number of copies of insert is 100, the molecular weight of plasmid is 3000 g/mol, and the molecular weight of insert is 500 g/mol. Using the formula:
\[ P = \frac{100 \times 3000}{500} \]
We get:
\[ P = 600 \]
So, the number of copies of plasmid is 600.