The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium stain...

Oriented fibres of extracted nucleohistone were employed as test material in a study of satisfactory fixation, embedding, and staining methods for structures containing a high proportion of nucleic acid. Fixation in buffered osmium tetroxide solution at pH 6, containing 10(-2)M Ca(++), and embedding in Araldite enabled sections of the fibres to be cut in which the orientation was well preserved...

Many methods are now available for achieving selective inhibition of cellular division among a variety of microorganisms. A few reports are available presenting analyses of the composition of bacterial cells grown in the absence of cell division. It was shown by Nickerson and Sherman (1952) with Bacillus cereus that homogenous populations of greatly elongated cells (devoid of interior partition...

A technique appropriate to investigation of the developmental fates of distinct embryonic cell types is described and the fate of a particular type of chick myoblast (CMR-I) examined. CMR-I myoblast clones are morphologically different from other chick myoblast clone types and can readily be identified in living cultures. After two weeks of culture CMR-I myoblast clones were collected, aggregat...

The ribbon-like macronucleus of Euplotes eurystomus pinches in half amitotically at each cell division. Several hours before the actual division two lightly staining duplication bands (reorganization bands) appear at the ends of the nucleus and approach each other slowly, finally meeting near the middle. Distal to the bands, that is, in regions through which the bands have already passed, the c...

Information on nuclei in bacterial spores was both scanty and inconsistent until the Feulgen technique, in the hands of Stille (1937), Delaporte (1939), Schaede (1939) and others, revealed Feulgen positive matter in the shape of a granule or rodlet at the periphery of the majority of mature, resting spores of many well known Bacilus species, including Bacllus megaterium. A more detailed picture...

The sequential morphological and cytochemical alterations in HeLa cells infected with adenovirus types 1 to 4 are described. Each of the four viruses studied led to consistent and reproducible cytological changes not observed in uninfected control cultures. All four agents produced striking and characteristic changes in the nuclei of infected cells. Alterations in the cytoplasm, though present,...

Besides photometric cytometry (PC), fl uorescence microscopy combined with computerised image analysis, i.e. image cytometry (IC), offers an alternative tool for assessing genome size. These techniques allow direct visualization of hyphae and simultaneous measurement of nuclear fl uorescence intensity. We developed a simple method for quantitative evaluation of nuclear DNA in fungi using DAPI-I...

cytophotometry provides means for rapid cell cycle analysis of lange cell populations (6, 24). Although a number of FMF and impulse cytophotometry studies on cells in vivo and in vitro have been recently reported (2, 14-19, 21-27), exten sive use of this methodology in clinical studies has been hindered by problems in sample preparation, the need for large samples, and the length of processing ...