title: Differential staining of Dugesia tigrina sister chromatids.
abstract: Planaria were cultured in a solution of bromodeoxyuridine (BrdU) for 24 h in an attempt to produce sister chromatid differential staining (SCD) and sister chromatid exchange (SCE). SCD was produced when planaria were cultured in planarian saline solution (PSS) containing 5 x 10(-5) M BrdU. Colchicine (0.02%) was added to the BrdU/PSS culture medium 8 to 10 h before sacrifice. Animals were then vigorously dissociated into cells, centrifuged, and fixed in Carnoy's solution. Slides were prepared using the air-drying method, allowed to age for at least 1 day, stained with the fluorochrome Hoechst 33258, exposed to high intensity incandescent light, stained with Giemsa solution, and mounted. This method is the first reported SCD/SCE investigation in the Platyhelminthes and consistently yielded second division metaphases exhibiting SCD and third division metaphases exhibiting non-reciprocal SCE's composed of unifilarly BrdU-labelled DNA.
authors.affiliation: Department of Biology, Long Island University, Brooklyn Center, New York 11201.
authors.forename: J R
authors.initials: JR
authors.lastname: Edelman
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lin
mesh_terms: D000818:Animals; D002842:Chromatids / Q000648:ultrastructure*; D010932:Planarians / Q000235:genetics*; D013194:Staining and Labeling