Two-wavelength cytophotometry: the choice of the wavelengths from a practical point of view.

Methods in use for the choice of the two-wavelengths and the effect of a faulty choice of the two wavelengths in the two-wavelength cytophotometric method of Patau and Ornstein are studied by means of a computer simulation and in practice upon pararosaniline-Schiff stained nuclei. A simplification of the measuring strategy is proposed without affecting the accuracy.