PARTITION OF MACROMOLECULES IN AQUEOUS TWO-PHASE SYSTEMS 



35 



straight line indicating that in this phase system it is mainly the surface 

 area which determines the K value. An upper limit of the K value is 

 obtained which is probably due to incomplete separation of the phases. 

 No K value less than lO"** has been observed even for very large particles. 



^O 50 220m)u^ 

 surface area 



Fig. I. Relation between the partition coefficient, K, and the surface area of 

 virus particles and protein molecules. The data of Table I are plotted in this figure. 



The fact that the virus concentration is looo to lo coo times higher in 

 one phase than in the other, may be utilized for the concentration and 

 purification of viruses [3, 6, 7, 8, 9, 10]. 



tablp: II 



Distribution of Some Nucleic Acid Preparations in a Na Dextran Sulphate- 

 Methylcellulose System 



C, = concentration in top phase, C,, = concentration in bottom phase, V,,= 

 volume of bottom phase, a — amount of nucleic acid collected at the interface 

 (Lif et al. to be published; for experimental details see ref. [3]). 



Nucleic acid 



5,0,,, 



A'.= 





RNA from yeast 

 DNA from calf thymus (I) 

 DNA from calf thymus (II) 

 DNA from calf thymus (III; 

 DNA from phage Tz (I) 

 DNA from phage T2 (II) 

 DNA from phage T2 (III) 



3-5 

 20-4 



21-8 

 22-5 

 3I-I 

 31-5 

 33-0 



0-67 



o- 17 

 014 

 o- 12 

 0012 

 o-o8 



0-02 



Partition of some nucleic acid preparations has recently been studied 

 [11] in a dextran sulphate-methylcellulose system. Preliminary results 

 are shown in Table II and Fig. 2. In this phase system a major part of the 



