Digital color analysis

Optical Sensors for Ions and Protein Based on Digital Color Analysis... 

Abstract A novel colorimetric method, digital color analysis (DCA), was proposed using a digital color analyzer and was applied to various quantitative analyses using chromatic-ity coordinates and suitable sensors for visual colorimetry based on the characteristics of human visual perception by virtual simulations based on digital color information. On the basis of DCA, we developed a visual colorimetric sensor for Li+, NH4+ and protein determination by the mixing of two kinds of lipophilic dyes, whose optimum mixing ratio... 

Fig. 1 Concept and data-processing diagrams for digital color analysis...

Digital image analysis will increase the number of usable dyes since it does not rely on the human eye for detection and differentiation. A digital image is acquired at excitation wavelengths relevant for the dyes applied, and separate detectors record individual colors. Thus, digital image analysis e.g. will allow the combination of fluorescent and immunoenzyme dyes. 

Gouaux and Vincent (1990) performed a comparative analysis of polluted versus unpolluted areas by means of infrared color photography, digitalization, and data processing. The change in the spectral response indicated by the visible and infrared bands and by a decrease of the vegetation index (IR/R) was attributed to the action of pollutants. In the same manner, Cox et al. (1991) found that lichens exposed to Cu concentrations >20 p-g g exhibited a significant shift of 2-3% of the spectral response. 

Sometimes a thorough examination of the artwork can determine authenticity. Forgers may use colors not available during the artist s life. Brushwork, themes, and techniques can be assessed. Unusual materials make a work suspect. Also, the usual methods can be applied to detect a forgery fluorescence, spectroscopy, X-rays, neutron activation analysis, radioactive dating and, more recently, digital analysis. 

The application of in situ hybridization (ISH) has advanced from short lived, non-specific isotopic methods, to very specific, long lived, multiple color fluorescent-ISH probe assays (FISH). Improvements in the optics, filter technology, microscopes, cameras, and data handling by software, have allowed for a cost effective FISH setup to be within reach of most researchers. The application of mFISH (multiplex-FISH), coupled to the advances in digital imaging microscopy, have vastly improved the capabilities for non-isotopic detection and analysis of multiple nucleic acid sequences in chromosomes and genes (1). 

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