Letter | Published:

Enzymatic Degradation of Ribonucleoproteins of Chromosomes, Nucleoli and Cytoplasm



IN experiments utilizing purified crystalline ribonuclease in conjunction with various staining procedures, it has been possible to demonstrate that chromosomes of higher plants and animals contain appreciable quantities of nucleic acid of the ribose type. These experiments have also shown that ribonuclease may hydrolyse ribonucleoprotein, and that the residual material (non-histone protein) can be digested by pepsin. Conversely, ribonucleoprotein may be hydrolysed by pepsin, and the residual material (ribonucleic acid) degraded by ribonuclease. Such combination treatments have provided information concerning the localization of ribonucleo-proteins, ribonucleic acid and non-histone proteins in nucleus and cytoplasm. The validity of these methods for diagnostic purposes rests upon the use of highly purified and carefully assayed enzymes, and the employment of an adequate series of controls to determine the influence of variables capable of modifying the histochemical reactions.

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