Fluorescence microcopy

Figure 4 Correction of improper chromosome attachments by activation of Aurora kinase (45). (a) Assay schematic, (i) Treatment with the Eg5 inhibitor monastrol arrests cells in mitosis with monopolar spindles, in which sister chromosomes often are both attached to the single spindle pole, (ii) Hesperadin, an Aurora kinase inhibitor, is added as monastrol is removed. As the spindle bipolarizes with Aurora kinase inhibited, attachment errors fail to correct so that some sister chromosomes are still attached to the same pole of the bipolar spindle, (iii) Removal of hesperadin activates Aurora kinase. Incorrect attachments are destabilized by disassembling the microtubule fibers, which pulls the chromosomes to the pole, whereas correct attachments are stable, (iv) Chromosomes move from the pole to the center of the spindle as correct attachments form, (b) Structures of the Eg5 inhibitor monastrol and two Aurora kinase inhibitors, hesperadin and AKI-1. (c) Spindles were fixed after bipolarization either in the absence (i) or presence (ii) of an Aurora kinase inhibitor. Arrows indicate sister chromosomes that are both attached to the same spindle pole. Projections of multiple image planes are shown, with optical sections of boxed regions (1 and 2) to highlight attachment errors. Scale bars 5 xm. (d) After the removal of hesperadin, GFP-tubulin (top) and chromosomes (bottom) were imaged live by three-dimensional confocal fluorescence microcopy and DIC, respectively. Arrow and arrowhead show two chromosomes that move to the spindle pole (marked by circle in DIC images) as the associated kinetochore-microtubule fibers shorten and that then move to the center of the spindle. Time (minutes seconds) after the removal of hesperadin. Scale bar 5 (cm.

The technique used for the investigation of specific interaction of phospholipase A2 with substrate monolayers is the fluorescence microscopy. This method is very well known for studying the formation of solid-analogous lipid domains during the main i ase transition in lipid monolayers using a number of different fluorescence microscopy systems [7-9]. Recently it could be shown that fluorescence microcopy is also very suitable to study protein-lipid interactions at monolayers [2-6]. The fluorescence film balance used in all following experiments has been described elsewhere [7]. Materials and experimental procedure are briefly given in the text. A detailed description can be found in the cited papers [7,8]. 

The 2PA effect has been widely involved in numerous appheations as reviewed by Prasad et al. [25], such as frequency-up conversion lasing [26], optical power limiting [27,28], microfabrication [29,30], optical data storage and processing [31 ] and biological or medical applications [32]. As this chapter, which addresses 2PA of lanthanide complexes, will concern mainly biological applications, we will focus in this part on two-photon excited fluorescence microcopy in biology. 

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