Expression of bcr-abl mRNA in individual chronic myelogenous leukaemia cells as determined by in situ amplification

Laser scanning cytometry of mitosis: state and stage analysis

Here we use a concept of cell state, which can be defined as the conjunction of expression levels of an arbitrary number of biomolecules or modifications thereof that oscillate, to classify mitotic cells. We describe detection of cell states with quantitative immunofluorescence measurements performed by laser scanning cytometry. This platform allows both measurement of the cell states, capture of cell images within those states, and subsequent analysis of each image to classify by traditional mitotic stages based on nuclear morphology.

Laser scanning cytometry and tissue microarray analysis of salinity effects on killifish chloride cells

The effects of salinity on chloride cells (CC) and Na+/K+-ATPase content in gill epithelium of euryhaline killifish Fundulus heteroclitus were analyzed using laser scanning cytometry (LSC) and tissue microarrays (TMAs). Salinity acclimations consisted of acute transfer from freshwater (FW) to 1× seawater (SW) and gradual transfer from FW to 2.4× SW. Suspensions of dissociated gill epithelial cells were stained with DASPMI and evaluated using LSC. CC number and volume are proportional to external salinity, being lower in FW(0.5±0.2×105 and 405±32 μm3,respectively) and higher after 5 weeks in 2.4× SW(3.7±0.9×105 and 2697±146 μm3,respectively). TMAs were constructed from fixed gill tissues and developed using antibody for Na+/K+-ATPase to visualize CCs in situ and compare their characteristics with isolated CCs. Na+/K+-ATPase content per CC increases transiently (from 2.2±0.5×106 to 4.8±1.1×106relative fluorescence units, RFU) after 1 week of acute acclimation to 1× SW but returns to baseline values(2.4±0.5×106 RFU) within 5 weeks. In contrast, gradual acclimation to 2.4× SW permanently increases Na+/K+-ATPase content per CC (from 2.0±0.8×106 to 6.7±2.7×106 RFU after 5 weeks). CC size in situ did not correlate well to salinity because of basolateral membrane infoldings. Taken together, these data suggest that euryhaline fishes are capable of sensing environmental salinity to utilize transient short-term and permanent long-term adaptations for coping with salinity changes. These results also demonstrate the power of LSC and TMA for comparative biology.

Clinical applications of laser scanning cytometry

This study reviews existing and potential clinical applications of laser scanning cytometry (LSC) and outlines possible future developments. LSC provides a technology for solid phase cytometry. Fluorochrome-labeled specimens are immobilized on microscopic slides that are placed on a conventional epifluorescence microscope and analyzed by one or two lasers. Data comparable to flow cytometry are generated. In addition, the position of each event is recorded, a feature that allows relocalization and visualization of each measured event. The major advantage of LSC compared with other cytometric methods is the combination of two features: (a) the minimal clinical sample volume needed and (b) the connection of fluorescence data and morphological information for the measured event. Since the introduction of LSC, numerous methods have been established for the analysis of cells, cellular compartments, and tissues. Although most cytometric methods use only two or three colors, the characterization of specimens with up to five fluorochromes is possible. Most clinical applications have been designed to determine ploidy and immunophenotype; other applications include analyses of tissue biopsies and sections, fluorescence in situ hybridization, and the combination of vital and nonvital information on a single-cell basis. With the currently available assays, LSC has proven its wide spectrum of clinical applicability in slide-based cytometry and can be introduced as a standard technology in multiple clinical settings.