142 ALEXANDER L. DOUNCE 



tained by the freeze-drying technique and subsequently subjected to micro- 

 incineration. 



8. Miscellaneous References 



It has not been possible in the preceding two sections to cover the perti- 

 nent Uterature completely although every effort has been made to convey a 

 balanced impression of concepts and investigations current when these 

 sections were written. For the benefit of those seeking further information, 

 a few additional references bearing on the chemistry and physiology of 

 cell nuclei will now be given. 



The following material is in part concerned with techniques of isolation of cell 

 nuclei from various tissues: isolation of nuclei from cells of the cerebral cortex by a 

 procedure involving the use of very dilute citric acid;i*' isolation of cell nuclei from 

 thyroid cells by a citric acid procedure;'" isolation of cell nuclei from normal and 

 leukemic mouse spleen;'"' '^^ isolation of muscle cell nuclei by a citric acid method;'^* 

 and an analysis from the standpoint of morphology and histochemistry of cell nuclei 

 isolated from mouse liver in various aqueous media.'*' The ribonuclease activity of 

 isolated nuclei from normal and malarial parasitized chicken erythrocytes has been 

 investigated,'" and a new histochemical procedure for the determination of xanthine 

 oxidase has failed to show any of this enzyme in nuclei.'*^ Isolation techniques have 

 been used in a study of the immunochemical relationship between cell nuclei, cell 

 cytoplasm, and the products of the cell cytoplasm,'*' and in a study of the uptake of 

 (S**-labeled sulfate by cell nuclei.'*" The action of anticoagulants on cell nuclei has 

 been studied,'*'"'*' and work has been done on the amino acids of isolated cell nu- 

 glgi 164-166 The DNA content of sea urchin gametes has been studied,'*' and the rela- 

 tionship of arginine content to DNA content of erythrocyte nuclei and sperm of some 

 species of fish has been studied.'** Finally, further important and fascinating studies 

 have been made of the effect of the removal of nuclei (by microdissection) from single 



" D. Richter and R. P. Hullin, Biochem. J. 48, 406 (1952). 



^^ J. Rerabek, Biochim. et Biophys. Acta 7, 482 (1951). 



" M. L. Peterman and R. M. Schneider, Cancer Research 11, 485 (1951). 



" N. A. Mizen and M. L. Peterman, Cancer Research 12, 727 (1952). 



" D. S. Robinson, Biochem. J. 62, 629 (1952). 



** F. Zajdela and G. A. Morin, Rev. hematol. 7, 628 (1952). 



" Z. B. Miller and L. M. Kozloflf, J. Biol. Chem. 170, 105 (1947). 



*s G. H. Bourne, Nature 172, 193 (1953). 



*9 A. M. Schectman and T. Nishihara, Science 111, 357 (1950). 



*« E. Odeblad and H. Bostrom, Exptl. Cell Research 4, 482 (1953). 



*' E. Kradolfer, Experientia 8, 186 (1952). 



*2 N. G. Anderson and K. M. Wilbur, /. Gen. Physiol. 34, 647 (1951). 



*» H. S. Roberts and N. G. Anderson, Exptl. Cell. Research 2, 224 (1951). 



*^ J. Blumel and H. Kirby, Proc. Natl. Acad. Sci. U.S. 34, 561 (1948). 



** B. R. Brunish, D. L. Fairley, and J. M. Luck, Nature 168, 82 (1951). 



**E. E. Polli and A. Bestetti, Experientia 8, 345 (1952). 



*' D. Elson and E. Chargaff, Experientia 8, 143 (1952). 



*« R. Vendrely and C. Vendrely, Nature 172, 30 (1953). 



