A $\text{DNA}$ solution of $50 \: \mu g \: mL^{-1}$ concentration gives an absorbance of $1.0$ at $260 \textit{ nm}$. An aliquot of $20 \: \mu L$ from a $50 \: \mu L$ purified plasmid solution is diluted with distilled water to a total volume of $1000 \: \mu L$. The diluted plasmid solution gives an absorbance of $0.550$ at $260 \textit{ nm}$. The concentration of the purified plasmid in $\mu g \: \mu L^{-1}$ (rounded off to two decimal places) is ________.