DNase--a likely probe of juxtatranscriptional DNP

The acridine orange-DNase sequences applied to rat lymphoid cells resulted in granular products within the cell nucleus. Staining with uranyl acetate rendered the granules very opaque. Most of the coarse deposits lay adjacent to condensed chromatin. Minute granules were found in dispersed chromatin as well as in the nucleolus and in heterochromatin regions. Phosphotungstic acid staining revealed the protein constituents of these deposits. The procedure is suggested an electron microscopic demonstration of DNase protein bound to acridine orange modified beaded chromatin juxtaposed to transcription units.