Quantification of nuclear non-histone proteins by Feulgen--Naphthol Yellow S cytophotometry

Owing to the accumulation of nuclear non-histone protein (NHP) (a) in cells entering the cell cycle from the quiescent state and (b) in continuously cycling cells during G1 phase, a simultaneous determination of DNA and nuclear NHP is of high potential utility in cell kinetic studies. This paper provides guidelines for a Feulgen--Naphthol Yellow S staining technique for this purpose. It discusses details of the preparation and quantification procedures, and reviews the evidence for a quantitative relationship between nuclear Naphthol Yellow S binding and nuclear NHP.