Abstract
Rat tissue sections were freed from nucleic acids by enzymatic or chemical extraction methods, immersed in solutions of nucleic acids from various sources and stained with toluidine blue.
Tissue sections immersed in solutions of DNA showed intense nuclear and cytoplasmic staining; similar results were obtained with tissue sections placed in solutions of RNA. Thus both DNA and RNA can bind to nuclear and cytoplasmic sites in tissue sections freed from nucleic acids. The experiments indicated however that in vitro binding of nucleic acids to tissue sections was not specific to original sites of nucleic acid binding and the reactions showed no particular species or organ specificity.