Ag-staining of nucleolus organizer regions of chromosomes after Q-, C-, G-, or R-banding procedures

Metaphase chromosome preparations were made from leukocyte cultures of normal individuals. The cells were fixed in methanol:acetic acid (3:1 v/v), then dropped on cold, wet slides which were air-dried before storage at 4 degrees C. The slides were stained to identify the chromosomes by one of the following procedures: (1) Quinacrine. Slides were stained for 10 min in quinacrine mustard solution, rinsed in running tap water for 2 min, and mounted in Tris-maleat buffer, pH 5.6.