Histone and DNA detection in swollen spermatozoa and somatic cells, by immunofluorescence

A method of swelling spermatozoa and other cells, which leads to the exposure of nuclear antigens is described. By applying the indirect IFT on these swollen cells with sera containing antibodies to nuclear antigens, and by comparing the results to those obtained in other tests (measuring anti-nuclear antibodies), the following conclusions could be drawn: (a) By swelling human spermatoza, nuclear antigens of the sperm are exposed, and can be used for the detection of antibodies directed against them. (b) Heterlogous antibodies to histones F2al, FIa2 and F3 which can not be detected in the indirect IFT on rat liver cells, become detectable after swelling of these cells. (c) Mature human spermatozoa contain, in addition to double-stranded DNA and protamine, small amounts of histone F2b and F2a2. (d) In mature human spermatozoa histone F1 is absent.