You searched for: “cytophotometry
1. The study of chemical compounds inside a cell by means of a cytophotometer.
2. The study of cells and chemical compounds within cells by means of a cytophotometer.
3. A method of measuring the absorption of monochromatic light by stained microscopic structures; for examlple, chromosomes, nuclei, and whole cells, with the aid of a photoelectric cell.

Also used to measure emitted light from such objects by fluorescence in combination with selected fluorochrome dyes.