Feulgen Staining of Rabbit Spermatozoa: Hydrolysis Time and Distribution of Chromatin

Abstract

A period of 12–16 min was found to be optimum for hydrolysis, in 1 N HCl at 60 C, of rabbit spermatozoa for quantitative Feulgen staining. The gradient of optical density along the longitudinal axis of Feulgen-stained rabbit sperm cell nuclei followed a typical pattern, deviating from a linear regression. A 2 μ diameter spot centered at the midpoint of the nucleus with uniform density approximating the mean density was present in most of the cells measured. This central spot can be used with reliance in DNA assays using light beam core sampling methods of microspectrophotometry.