DNA graph characterization for the line digraph of dicycle with $\left\lfloor{\frac{n}{3}}\right \rfloor$ chords, $\infty$-digraph $C_n \cdot C_p$, and 3-blade-propeller $C_n \cdot C_p \cdot C_q$.

DNA graph has important contribution in completing the computational step of DNA sequencing process. Using $(\alpha,k)$-labeling, several families of digraphs have characterized as DNA graphs. Dicycles and dipaths are DNA graphs, rooted trees and self adjoint digraphs are DNA graphs if and only if their maximum degree is not greater than four, while the $m^{\text{th}}$ line digraph of dicycle with one chord is a DNA graph for all $m\in\mathbb{Z}^+$. In this paper we construct $(\alpha,k)$-labeling to show that for all $m\in\mathbb{Z}^+$, the $m^{\text{th}}$ line digraph of dicycle $C_n$ with $\left\lfloor{\frac{n}{3}}\right \rfloor$ chords are DNA graphs for $n\geq 6$, and the $m^{\text{th}}$ line digraph of $\infty$-digraph $C_n\cdot C_p$ and 3-blade-propeller $C_n\cdot C_p \cdot C_q$ are DNA graphs for $n\geq 3$ and certain values of $p$ and $q$.