A factorial combination of pretreatments, fixatives, and stains was examined to identify the best available method for staining the chromosomes of strawberry (Fragaria × ananassa Duch. ‘Chandler’) root-tip cells. Three pretreatments ( a -bromonaphthalene, p -dichlorobenzene, and 8-hydroxyquinoline), three fixatives (Farmer’s fluid, Carnoy’s fluid, and Newcomer’s fluid), and five stains (acetocarmine, alcoholic hydrochloric-acid carmine, altered carbol fuchsin, lacto-propionic orcein, and leucobasic fuchsin) were tested. Pretreatment with either a -bromonaphthalene (saturated aqueous) or 8-hydroxyquinoline (2 mM) for 5 hours at 14C, overnight fixation in Farmer’s fluid, hydrolysis in 1 N HCl (15 minutes at 60C), and staining with altered carbol fuchsin produced chromosome preparations superior to other treatment combinations. Treatment with a-bromonaphthalene, Farmer’s fluid, and alcoholic hydrochloric-acid carmine (2 days at 25C) also produced acceptable chromosome preparations.
Owen, Henry R. and Miller, A. Raymond, "A Comparison of Staining Techniques for Somatic Chromosomes of Strawberry" (1993). Faculty Research & Creative Activity. Paper 144.