title: Cytological analysis and sorting of a human supernumerary minichromosome.
abstract: In a newborn female, an abnormal karyotype, 46,XX/47,XX,+mar/47,XX,+9, was found associated with several malformations. The marker chromosome was present in 70% of peripheral blood lymphocytes, and its size appeared to be less than half of the smallest chromosomes. Several differential staining methods provided no indication as to its origin.Chromosomes isolated from EBV-immortalized lymphocytes of the patient were fractionated on a FACS-440. The marker was resolved as a sharp peak in the region close to the chromosomal debris: its DNA content seemed to be close to 40% of chromosomes 21 and 22.About 580000 minichromosomes were sorted. In order to optimize cloning conditions, a pilot cloning experiment was performed on a pool of sorted chromosomes 9, 10, 11 and 12.
authors.affiliation: Dipartimento di Genetica e Microbiologia 'A. Buzzati-Traverso', Univ. di Pavia, Via S. Epifanio 14, 27100, Pavia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Ferretti
authors.forename: E
authors.initials: E
authors.lastname: Raimondi
authors.forename: L
authors.initials: L
authors.lastname: Davis
authors.forename: M
authors.initials: M
authors.lastname: Romagnoni
authors.forename: L
authors.initials: L
authors.lastname: De Carli
authors.forename: V
authors.initials: V
authors.lastname: Sgaramella
authors.forename: B D
authors.initials: BD
authors.lastname: Young