Laser-scanning cytometry fluorescence

In addition to flow cytometers, cytometric instrumentation has evolved to include Laser Scanning Cytometry (LSC). The LSC is a cross between a flow cytometer and an imaging cytometer. Data are equivalent to the flow cytometer but is slide-based. Endpoints include light scatter and fluorescence, but the instrument can also record position of individual cells on the slide so that cells of interest can be relocated and re-evaluated or photographed. LSC is valuable when cell morphology is important. 

Viability-based technologies Direct epifluorescent filter microscopy Membrane laser scanning Fluorescence cytometry Fluorescence flow cytometry... 

TAT-peptide modified liposomes were prepared and cellular association and intracellular distribution of (double) fluorescently labelled particles were assessed by flow cytometry and confocal laser scanning microscopy. 

Fluorescence detection confocal or laser scanning devices, CCD cameras, near-infrared imaging, surface plasmon resonance imaging, flow cytometry (for microspheres)... 

Fluorescent reporters allow detection in a single cell with epifluorescence and confocal laser scanning microscopy (Cormack et al., 1996 Tombolini et al., 1997 Phillips, 2001) or allow quantitative single-cell analysis with flow cytometry (Cormack et al., 1996 Valdivia and Ramakrishnan, 2000), enlarging their potential scope of use. 

Lemarchand K, Parthuisot N, Catala P, Lebaron P (2001) Comparative assessment of epifluores-cence microscopy, flow cytometry and solid phase cytometry in the enumeration of specific bacteria in water. Aquat Microb Ecol 25 301-309 Lepeuple AS, Delabre K, GUouppe S, IntertagUa L, de Roubin MR (2003) Laser scanning detection of FISH-labelled Escherichia coli from water samples. Water Sd Technol 47 123-129 Lisle JT, Hamilton MA, Willse AR, McFeters GA (2004) Comparison of fluorescence microscopy and sohd-phase cytometry methods for counting bacteria in water. Appl Environ Microbiol 70 5343-5348... 

As with flow cytometry, multiparameter apoptosis assays may also be performed by confocal laser scanning microscopy (CLSM). Using the approach similar to that detailed above for flow cytometry, we have examined NADPH content, mitochondrial membrane potential (CMX Rosamine fluorescence), and mitochondrial mass (Mitotracker Green), by CLSM. Figure 3 shows an example of a typical multiparameter assay performed by confocal microscopy. 

Fig. 4. Combined use of flow cytometry/cell sorting and confocal laser scanning microscopy. TNF-a/ActD treated Hepa-1 cells were stained with CMX Rosamine and then analyzed for mitochondrial membrane potential and NAD(P)H fluorescence (A). Cells in different regions of the cytogram were then sorted, and subsequently stained with the DNA fluorochrome Hoechst 33342. These cells were then examined by CLSM. (B), (C), and (D) show three-dimensional reconstructions of nuclei from cells sorted from healthy, early apoptotic, and late apoptotic populations. Whereas healthy cells show normal round nuclei, early and late apoptotic cells show progressive chromatin condensation/margination and nuclear fragmentation.

The laser scanning cytometer (LSC) is a microscope-based cytofluorometer that combines advantages of flow cytometry and image analysis and is finding wide applicability in many disciplines of biology and medicine (see reviews in refs. 8,9). LSC measures cell fluorescence rapidly and with similar accuracy as flow cytometer. However, since the xy coordi-... 

The Chemunex Scan RDI uses a base technology of solid-phase cytometry which will only detect intact, viable cells. It uses a nonfluorescent substrate that is enzymatically cleaved by intracellular nonspecific esterase enzymes to activate the substrate to a fluorescent form for detection by laser cytometry. 

In solid-phase cytometry (SPC), microorganisms are analysed by a combination of both epifluorescence microscopy and flow cytometry [139], Air is impacted on a water-soluble polymer film present in a standard Petri dish (polyvinyl alcohol plate). After filtration, viable cells are labeled. The filter is scanned by a laser in a solid-phase cytometer. Using different software, fluorescent particles are distinguished from microorganisms. 

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