Who Has Seen Nucleolus for the First Time?

Nucleoli observed in HeLa cells (left) and isolated HeLa cell nuclei (right) by differential interference microscopy. (Images courtesy of David L. Spector [left] and Thoru Pederson [right].) The first properly documented accounts of the nucleolus were made independently by Wagner (1835) and Valentin (1836, 1839).

Who first discovered the nucleolus?

Felice Fontana in 1774 discovered nucleolus. It is a dense region rich in DNA, RNA, and proteins that are formed from nucleolar organizing regions which are specific regions on chromosomes.

Can nucleolus be seen?

The nucleolus is typically visible as a dark region of low DNA density by DAPI DNA stain, due to the abundance of ribosomal RNA and proteins assembling throughout most of the nucleolus.