Fluorescence volume exclusion signals are utilized to evaluate cell volume. Cells are suspended in a medium which is furnished with a fluorescent dye which neither penetrates nor adheres to the cells. Cells are analyzed by an optical flow cytometer, with illumination which causes the dye medium to fluoresce....http://www.google.com.hk/patents/US4284355?utm_source=gb-gplus-share專利 US4284355 - Automated method for cell volume determination
