* DNA phages: Most phages have double-stranded DNA (dsDNA) as their genetic material. Examples include the well-studied phages T4, lambda, and M13.
* RNA phages: A smaller group of phages have single-stranded RNA (ssRNA) as their genetic material. Examples include the Qβ phage and the MS2 phage.
The specific type of nucleic acid and its structure (single-stranded or double-stranded) are important characteristics that determine the phage's life cycle and its interactions with the host bacteria.
