What is the largest structural organization of DNA?

The largest structural organization of DNA is best represented by chromatin. Chromatin is a complex of DNA and proteins (histones) that organizes DNA within the nucleus of eukaryotic cells. It exists in two forms: euchromatin, which is loosely packed and accessible for transcription, and heterochromatin, which is more tightly packed and usually inactive.

Chromatin undergoes further levels of organization; when it condenses during cell division, it forms chromosomes. The structural hierarchy from the linear DNA strand to the 30 nm fiber represents progressive levels of DNA packaging, but it is the chromatin structure that encompasses these forms and represents the largest and most complex organization of DNA in the functional context of the cell. This makes chromatin the most comprehensive answer regarding the structural organization of DNA.