P32 UPTAKE BY NUCLEI

摘要: 1. A method for isolating nuclei in quantity from mammalian tissues is described. 2. The rate of uptake radioactive phosphorus by found to be quite rapid. was shown not taken up exchange. 3. Nuclei tumors accumulate more than normal liver nuclei. This due mitotic activity and a form metabolism peculiar tumor cells. 4. specific activities cytoplasm are compared. 5. 60 70 per cent the nuclear present as nucleoprotein 1 hour 5 days after it administered. In lymphoma 90–95 fraction 1–5 6. nucleoprotein, lipid, acid-soluble fractions 7. From P32 calculated that new nucleus synthesized on average once every 27 hours. agreement with observed growth tumor. 8. 7 x 104 molecules tetranucleotide second. 9. Irradiation 200 r. x-rays alters distribution cell, markedly increasing concentration shortly irradiation. decreases time It suggested altered correlated inhibition mitosis produced x-rays. 10. Continual synthesis takes place even cells which do undergo mitosis.