Cytochemical methods proposed for the demonstration of nucleoli were comparatively studied in order to obtain more specific visualization of nucleoli with a light microscope.
The amphibian cell culture derived from frog kidney tissue was successfully used in stain preparations of mitotic cells, and some modifications of staining methods resulted effective manifestation of nucleoli at mitotic phases.
Moderate extraction of RNA from fixed cells with perchloric acid or RNase was recognized more effective to the subsequent nucleolar stainings for the detection of persistent nucleoli in any kind of cultured cells.