ISSN:0886-1544    

DOI:10.1002/cm.970100102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0886-1544    

DOI:10.1002/cm.970100103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0886-1544    

DOI:10.1002/cm.970100104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThe progress in video microscopy is reviewed from its early inception, especially with respect to improvements of the microscope image quality. Very recent advances that provide serial optical sections and depth of field as thin as 0.1 μm and that make possible the recording of birefringent images of individual microtubules (25 nm in diameter) directly in live, dividing cells are also documented

ISSN:0886-1544    

DOI:10.1002/cm.970100105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractFluorescence microscopy, uniquely, provides the ability to examine specific components within intact, even living, cells. Unfortunately, high‐resolution conventional fluorescence microscopy is intrinsically a two‐dimensional technique and performs poorly with specimens thicker than about 0.5 μm. Probing the spatial organization of components within cells has required the development of new methods optimized for three‐dimensional data collection, processing, display, and interpretation. Our interest in understanding the relationship between chromosome structure and function has led us to develop the necessary methodology for exploring cell structures in three dimensions. It is now possible to determine directly the three‐dimensional spatial organization of diploid chromosomes within intact nuclei throughout most of the mitotic the ce

ISSN:0886-1544    

DOI:10.1002/cm.970100106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThe compartmentalization of eukaryotic cells by internal membranes and the subcellular localization of endogenous macromolecules by specific binding mechanisms are familiar concepts. In this report we present evidence that the cytoplasmic ground substance, which surrounds and contains the membranebound compartments, may also be compartmentalized by local differentiations of its submicroscopic structure that sort subcellular particles on the basis of size. The subcellular distribution of size‐fractionated, fluorescent tracer particles was studied in living cells by ratio imaging and fluorescence recovery after photobleaching (FRAP). Large and small particles showed different distributions within the cytoplasmic volume, suggesting that the large particles were relatively excluded from some domains. While the structural basis for this phenomenon is not yet understood in detail, ratio imaging of large and small particles can be used as an empirical tool to identify cytoplasmic compartments for further study. The cytoplasmic diffusion coefficient (Dcyto) and % mobile fraction of the large particles showed considerable spatial variation over the projected area of the cell, while Dcytoand % mobile fraction of the small particles did not. A model is presented to account for this difference. Based on this model, a method is proposed by which FRAP can be used to detect sol‐gel transitions in the cytoplasmic ground substance of living ce

ISSN:0886-1544    

DOI:10.1002/cm.970100107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractBacterial flagella have rotary motors at their base; embedded in the cytoplasmic membrane and powered by transmembrane ion gradients instead of ATP. Assays have been developed to measure the torque output of individual motors over a wide regime of load, to correlate the energizing proton flux with rotation speed and relate through genetic analysis motor structure to function. These assays promise substantial advances in understanding mechanochemical coupling in these motors. Here, I summarize the present status of our understanding of energy transduction in bacterial flagella and compare this with the case for muscle.

ISSN:0886-1544    

DOI:10.1002/cm.970100108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractVideo and digital image processing have been used to amplify the contrast of light microscopic images, making it possible to observe in real time the diffraction images of cell structures 10 times smaller than the Raleigh resolution limit of 0.2 μm. In this paper we discuss how quantitative analysis of diffraction images can be used to extract information about motion or structure at the nanometer level. This issue is considered in the context of a method for tracking the motion of kinesin‐coated beads on microtubules with 1–2 nm precision (Gelles et al.:Nature331:450–453,

ISSN:0886-1544    

DOI:10.1002/cm.970100109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA wide variety of specimens has been examined with our apparatus, a commercial version of which is being manufactured by Bio‐Rad/Lasersharp. The advantages expected of a confocal system have been realised in practice, the most striking advantage being the exclusion of glare from out‐of‐focus structures. This has made it possible to image cytological details in unflattened cells and intact tissues that were previously inaccessible to the light micro

ISSN:0886-1544    

DOI:10.1002/cm.970100110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractRecent advances in thin film optical coating technology significantly improve the filters available for fluorescence spectroscopy. Bandpass and long‐ and shortpass filters with very sharply defined edges can provide from 10−5to 10−6blocking within 10–15 nm of the transmission region and are ideal for use as excitation and emission filters. A variety of nonpolarizing dichroic beamsplitters for use in epi‐illumination configurations or in multiple emission configurations provides optimum longpass, shortpass, band reflection, or bandpass spectral control. These dichroics, used with high‐performance bandpass, longpass, or shortpass filters, form matched sets that optimize the signal‐to‐noise ratio and system efficiency for fluorescence spectroscopic systems in single or multiple dye applications. Specially designed dichroic beamsplitters are used to reduce excitation filter overheating. Other dichroic beamsplitters efficiently separate two planes of polarization in a narrow wavelength band. Rejection band filters can be used to measure the fluorescent dye Indo 1 with very low e

ISSN:0886-1544    

DOI:10.1002/cm.970100111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY