The nucleoid is the region in the prokaryotic cell that contains the main DNA material. As a side note, some DNA will be in other sections of the cell, but the primary material will be in the nucleoid. The nucleoid has an irregular shape compared to the nucleus of eukaryotic cells, which is circular.NA in the nucleoid is circular and may have multiple copies at any given time. Additionally, DNA in the nucleoid may be supercoiled, meaning it has twists in the circular shape that makes it more compact. As the cells grow, the DNA in the nucleoid may extend into the cytosol, or cellular fluid.