ISOLATION AND COMPOSITION OF PENTOSE NUCLEIC ACIDS 397 



TABLE III 

 Nucleotide Composition of PNA Isolated from Liver 



Prepa- Adenylic Guany- Cytidylic Uridylic 



ration Animal acid lie acid acid acid Pu/Py Method" Ref . 



° See page 395. 



from the liver of a variety of species of animals is presented in Table III 

 and will be considered first. It can be seen that the liver PNA preparations 

 of all the animals studied are rich in guanylic acid and cytidylic acid, and 

 poor in adenylic acid and uridj'lic acid. The ratio of purines to pyrimidines 

 is generallj' not far from unity. The preparations exhibit considerable 

 variation in nucleotide ratios, but no striking differences in the composi- 

 tion of liver PNA of different animals indicative of species-specificity can 



