New developments in quantitative imaging cytometry

Recent increases in the use of celland tissue-based experimental models in life sciences and drug discovery have fueled a demand for a combination of imaging and quantitative cytometry techniques. This demand has been met with the development of LSC, which has substantial advantages over other cellular analysis technologies, such as fluorescence image analysis (FIA) and flow cytometry (FC)1. FIA, FC and LSC can each be used to assay and quantify multiple cell components by measuring the fluorescence of cells that have been treated with one or more fluorescent dyes. FC and LSC can be used to measure light scatter in addition to fluorescence, as both result from interaction of the cells with a laser beam, as opposed to the mercury or xenon arc epi-illuminator typically used in FIA. The analytical capabilities of FC are severely limited for many applications, particularly for analysis of adherent cells and intact tissue samples. Events requiring time resolution—such as enzyme kinetics, drug uptake or efflux—cannot be analyzed on individual cells, and subcellular fluorochrome localization cannot be quantified. Furthermore, once a cell has been measured, it cannot be reanalyzed with another probe, and the sample cannot be stored for archival preservation. In addition, applications such as assessment of the morphology of a measured cell and smallsample analysis are difficult to perform with FC.