208 HUBERT S. LORING 



TABLE IV 



Adenine, Guanine, Cytidine, and Uridine Composition of Mitochondria, 

 Microsomes, and Nonsedimentable PNA Fraction from Normal Swiss 



Mouse Liver" 

 (/iM per 100 mg. TCA and alcohol-ether extracted powder) 



" The means and standard deviations of the means for six separate analyses of a pool of normal 

 mouse liver were as follows: adenine, 2.77 ± 0.05; guanine, 4.98 ± 0.05; total purine, 7.74 ± 0.05; cyti- 

 dine, 4.44 ± 0.11; uridine, 2.70 ± 0.04; total pyrimidine, 7.13 ± 12. 



* The fresh tissue from each pool was ground in 0.88 M buffered sucrose and fractionated by differential 

 centrifugation essentially as given by Hogeboom, Schneider, and Pallade.^' In VIb the tissue was stored 

 frozen for seven days before grinding. 



particularly by Claude^* and by Hogeboom, Schneider, and Pallade^^ has 

 provided relatively characteristic ribonucleic acid-containing cell com- 

 ponents for analytical study. [Cf. Donace, Chapter 18, and Hogeboom and 

 Schneider, Chapter 21.1 Such materials from different animal species and 

 from several types of tissue after extraction with trichloroacetic acid and 

 alcohol-ether to remove acid-soluble and lipid components, respectively, 

 have been analyzed directly for their ribonucleic acid components'''-''^ or 

 have been used for the extraction of the ribonucleic acid, which subse- 

 quently has been analyzed.^^ Similarly ribonucleic acids prepared from 

 liver and other animal tissues have been extensively analyzed. 2^- 69. 72. 73 



68 A. Claude, J. Exptl. Med. 80, 19 (1944); 84, 51 (1946). 



89 G. H. Hogeboom, W. C. Schneider, and G. E. Pallade, J. Biol. Chem. 172, 619 



(1948). 

 " A. Marshak, J. Biol. Chem. 189, 607 (1951). 

 " D. Elson and E. Chargaff, Federation Proc. 10, 180 (1951); Phosphorvs Metabolism 



2,331 (1952). 

 " F. Leuthardt and B. Exer, Helv. Chim. Acta 36, 500 (1953). 

 " E. Volkin and C. E. Carter, J. Am. Chem. Soc. 73, 1516 (1951). 



