/. WOODLAM) HASTINC.S AND VERXON C. BODE 301 



dual buffer added, however, as in the case of phosphate, the curve 

 goes through the origin. This indicates the absolute nature of the 

 salt requirement. 



Table 2 lists other compounds which have been tested for their 

 ability to fulfill the salt requirement. Several properties of each of 



THE EFFECT OF ADDED ALBUMIN 





_j 



< 



I- 



o 



MILLIGRAMS OF ALBUMIN ADDED 



Fig. 5. This figure illustrates the effect(s) of crystalline bovine serum albumin 

 upon the luminescent reaction. Each point is from a separate experiment. The 

 reaction mixture in each case was composed of O.4.") ml saturated ainmonium sul- 

 fate, 0.4r> ml of 0..") M Tris-maleate buffer, pH 6.!}. 0.1 ml of partially purified 

 enzyme (O.I mg protein). 0.1 m\ luciferin (hot water extract of freshly harvested 

 cells), crystalline bovine serum albiunin as indicated on the abscissa, and water to 

 a total volume of 2.0 ml. The reactions were initiated by adding the luciferin 

 last. It may be seen that an increased quantity of albumin results in an increased 

 yield of light from the luminescent reaction. The rate of the reaction (intensity) 

 is also greater. 



the salts must be considered in an evaluation of their relative effec- 

 tiveness. A few of these are: ionic strength, molecular size, solubility 

 (see, for example, K2SO4 in Fig. 6) , the potential for oxidizing or 

 reducing (e.g. KsFe (CN) ,; : Na^S^Oa) , and effectiveness as protein 

 precipitants. The possible multiplicity of effects, along with the 



