620 



A. W. Galston and D. C. McCune 



starch was stirred thoroughly and centrifuged down, the supernatant 

 being drawn off with a pipette and used for the peroxidase assay. 



For each electrophoretic analysis, the second leaf sheaths of ca. 

 30-40 plants were harvested. The final homogcnate represented ca. 

 250 mg. fresh weight of tissue per ml. This homogenate was centri- 

 fuged at ca. 20,000 X gravity for 15 min. and the precipitate discarded. 

 The supernatant liquid was saturated with (NH4)2S04, and the pre- 

 cipitate removed by centrifugation (20,000 X gravity, 15 min.) 3 hrs. 

 later. The precipitate was dissolved in 2.5 ml. buffer, then dialyzed for 

 a total of 20 hrs. against three successive volumes of 200 ml. buffer in 

 the cold room. The final residue in the dialysis bag was again clarified 





o 

 < 



CO 



< 

 o 



o 



(E 

 UJ 

 0. 



GUAIACOL 



PYROGALLOL 



10 



DISTANCE CM. 



20 



Fig. 2. Klcctrophoiclic pattern of peroxidases from normal leaf sheath of corn. 

 Guaiacol or pyrogallol substrate. 



