420 



R. A. OLSON, F. S. BRACKETT, R. G. CRICKARD 



mixtures in water-jacketed tonometers provided with two 3-way 

 capillary stopcocks such that air could be removed by evacuation 

 prior to equilibration and the suspension finally introduced through a 

 nylon capillary tube into a cuvette previously swept with the gas 

 mixture. Experience showed this could be done without measurable 

 contamination by air. 



RESULTS 



The anaerobic dark treatment of Chlorella suspensions provides 

 ideal conditions for the rate recording of transient oxygen evolution. 



TIME IN MINUTE INTERVALS 



Fig. 1. Original rate recording of a typical O2 burst following anaerobic dark 

 adaptation, with accompanying O2 concentration curve dotted in. 



The long delay of sustained oxygen ev^olution (induction) by suffi- 

 cient anaerobic time eliminates the complex changes resulting from a 

 burst superimposed on a changing background rate. It also allows the 

 use of full gain of the rate-recording amplifier without overloading 

 by the oxygen concentrations prevailing at aerobic levels. Such a 



