Biomaterial Database

Soft x-ray lithographic studies of interphase chromosomes. 1980

L Manuelidis, and J Sedat, and R Feder

Soft x-ray absorption lithograph patterns of purified interphase human nuclei and chromosome arrays, imaged on PMMA resists, were examined by scanning EM. The patterns obtained were compared to those utilizing more conventional sources, including transmission EM, scanning EM, high voltage EM, and various light microscopic techniques. The x-ray resist images revealed orderly arrays of absorption profiles in the 3-dimensional specimen with both mild and more extensive developments of the resist. Dense chromatin at the edge of interphase nuclei revealed aligned periodic peaks on the order of 2200 A diameter, with substructure. The periodicity and alignment of interphase chromosomes were entirely consistent with birefringent data on nuclei indicating a high degree of 3-dimensional order. This degree of 3-dimensional order was observed in nuclei containing essentially DNA and histones with only very few other minor (probably structural) proteins. Sonication and nuclease treatment to disperse interphase chromosomes revealed similar absorption periodicities in individual chromosome fibers. Analysis of x-ray absorption profiles thus appears to offer significant new insights into the ordered structure of these defined biological specimens.

UI	MeSH Term	Description	Entries
D007399	Interphase	The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).	Interphases
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D009374	Neoplasms, Experimental	Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.	Experimental Neoplasms,Experimental Neoplasm,Neoplasm, Experimental
D011859	Radiography	Examination of any part of the body for diagnostic purposes by means of X-RAYS or GAMMA RAYS, recording the image on a sensitized surface (such as photographic film).	Radiology, Diagnostic X-Ray,Roentgenography,X-Ray, Diagnostic,Diagnostic X-Ray,Diagnostic X-Ray Radiology,X-Ray Radiology, Diagnostic,Diagnostic X Ray,Diagnostic X Ray Radiology,Diagnostic X-Rays,Radiology, Diagnostic X Ray,X Ray Radiology, Diagnostic,X Ray, Diagnostic,X-Rays, Diagnostic
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002877	Chromosomes, Human	Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.	Chromosome, Human,Human Chromosome,Human Chromosomes
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man