Quantitative DNA image cytometry by color image analyzer

: We developed a new method to analyze DNA quantitatively by a color image analyzer. A microscopic image of the nucleus stained with Feulgen's reaction, is taken by a CCD color camera and inputted in a color image analyzer. DNA quantity can be calculated directly from the RGB components of the color image instead of the monochrome image taken through band-pass filter, which is specific for the absorption of Feulgen's stain. It takes about 10 minutes to measure 500 nuclei by this method and its accuracy is almost the same as flow cytometry (CV = 3%). The nuclear color image can also be analyzed morphometrically. This method can select tumor cells in a usual cytologic specimen and measure their DNA contents.