Improvement of accuracy of scanning absorption measurement of nuclear DNA content in plants.

The effect of optical errors and stain variation on the accuracy of plant Feulgen-DNA absorption cytophotometry was investigated. Optical errors (glare, distributional error, and diffraction) were shown to cause important errors. A correction procedure of DUIJNDAM et al. (1980a) was successfully applied to eliminate them. Stain variation can also lead to serious errors and in case different samples are to be compared the use of an internal standard is imperative. Chicken red blood cells proved to be a reliable standard.