682 



ADVENTURES IIST RADIOISOTOPE RESEARCH 



extracted with CCI3COOH. The washed and dried tissue was then refluxed with 

 a chloroform methanol mixture (3 : 1) for 12 hours. After another extraction 

 with CCI3COOH, the extract had a negative reaction, which indicated the absence 

 of inorganic P. After one more extraction with CCI3COOH and chloroform-ether 

 the tissue was dissolved in 180 ml. KOH by keeping it at 37° for one night. Only 

 the hyflofilter was not dissolved. It was removed by centrifugation and the centri- 

 fugate was brought up to 200 ml. In order to be able to study the effect of repeated 

 precipitation of desoxyribosenucleic acid two halves of this volume were treated 

 separately. 5 per cent CCI3COOH and 20 ml 0.2 N HCl were added to each solution. 

 From the 2 desoxyribosenucleic acid precipitates obtamed, one (A) was dis- 

 solved in 1 N KOH solution and repricipitated and ashed, while the other (B) 

 was ashed after the first precipitations. The filtrate containmg the ribosenucleoti- 

 des, obtained after precipitation of the desoxyribosenucleic acid, was neutrahzed 

 and brought to 300 ml. After neutraUzation a minor precipitate was thrown 

 down. This precipitate was found to be only shghtly radioactive. The total P of 

 the neutrahzed solution was ashed and its P content (total P) determined. A larger 

 aliquote, i.e., 125 ml, was used to determine the inorganic P content of the solu- 

 tion. The method of Delory was used and 2 ml cone. NH3 -f 10 ml 2.5 per cent 

 CaClg + 10 ml 0.5 per cent MgC03 were added to the solution. The precipitate 

 obtained was centrifuged, washed with 2 per cent NH3 and dissolved in a 10 per 

 cent CCI3COOH solution. An aUquote was used for the colorimetric determination 

 and from another ahquote, to which 80 mgm inactive Na^HPO^ had been added. 

 P was precipitated as magnesiumammonium phosphate. 



RESULTS 



Table 1. — Values obtained for the Phosphorus Content of Fractions 



Sample 



Plasma (3 ml) 



Sarcoma tissue (0.593 gm) , 



A. (reprecipitated) 



Desoxyribosenucleic acid 



Total P in filtrate obtained after removal of desoxyribose- 

 nucleic acid 



Inorganic P in filtrate 



Ribosenucleic acid 



Etheric phase 



B. (not reprecipitated) 



Desoxyribosenucleic acid 



Total P in filtrate, obtained after removal of desoxj^ribose- 



nucleic acid 



Inorganic P in filtrate 



Ribosenucleic acid P 



Etheric phase 



P content 

 in mgm 



0.165 

 (inorganic) 



0.265 

 4.425 



0.3087 

 7.1163 

 0.0026 



5.375 



7.80 

 0.327 

 7.473 

 0.0071 



P content per gm 

 tissue in mgm 



0.055 



(inorganic P 



per ml 



plasma) 



0.447 



50.2 



80.6 



61.1 



84.7 



Ribosenucleic acid P = total P in filtrate — inorganic P in filtrate. 



