The cellular material solely composed of DNA and proteins is chromatin.

Here's why:

* DNA: Chromatin is made up of DNA, which carries the genetic instructions for the cell.

* Proteins: The DNA in chromatin is tightly wrapped around histone proteins. These proteins help organize and compact the DNA, making it more manageable within the nucleus.

Other cellular components contain either DNA or proteins, but not both:

* Ribosomes: Composed of RNA and proteins, responsible for protein synthesis.

* Mitochondria: Have their own DNA but also contain many proteins.

* Lysosomes: Primarily composed of proteins.

Let me know if you have any more questions!