

Yeast Extracts 



Isolated 80 S Particles 



Fig. 8. Ultracentrifuge patterns of yeast extracts and isolated 80 .S' particles. 



(a) Yeast extract in water, 12 minutes after reaching; speed of 42,040 r.p.m. 



(b) Yeast extract stored in water for 1 week, 12ininiites after reaching speed of 

 42,040 r.p.m. o i 



(c) Yeast extract in 0.15 iM NaCl, 12 minutes after reaching speed of 42,040 r.p.m. 



(d) 80 ,S particles isolated by three cycles of centrifugation in 0.0015 M KH2PO4, 12 

 minutes after reachhig speed of 42,040 r.p.m. 



(e) 80 S particles after three cycles of centrifugation and then dialysis in 0.0025 If 

 K2HPO4, 0.0025 M KH,P04, and 7.5 x 10"* 31 CaCl,, 56 minutes after reaching speed 

 of 20,410 r.p.m. ^ ^ 



(/) 80 *S' particles after three cycles of centrifugation in 0.0025 M K.,HP04 0025 31 

 KH,P04, 0.001 31 MgSO^, and 7.5 X 10-* 31 CaCL, 48 minutes after reaching speed of 

 20,410 r.p.m. (Chao and Schachman, 1956). 



