COMPLEMENT 159 



A metliod wliicli lias l)eeii used with success in this laboratory 

 is giv'en by Boerner and Lnkens (1939). This is a modification of 

 the original procedure of Sonnenscheine. The serum is obtained 

 and an equal volume of the following mixture is added : sodium 

 acetate — 12.0 grams; boric acid — 4.0 grams; sterile distilled Avater 

 q.s. — 100.0 e.c. The mixture is tlion stored in tlie ice ])ox and will 

 keep for relatively long periods of time. 



Effect of Heat on Complp:ment. — The optimum temperature 

 for complement action is 37° C, but it loses its activity within a 

 few hours at this temperature. Manwaring (1906) studied the 

 effect of higher temperatures on complement and found that notice- 

 able diminution in titer occurs within 10 minutes at 49° C, al- 

 though traces are present at the end of one hour. At 51° C, there 

 is greater diminution in 10 minutes and complete inactivation in 

 35 minutes. When a temperature of 53° C. is employed for 14 

 minutes the lytic property of complement disappears completely. 

 He found also that complete inactivation occurs in 12 minutes at 

 55° C, 8 minutes at 57° C 4 minutes at 59° C, and 2 minutes at 

 61° C. 



Reversibility of the Reaction. — Gramenitski (1912) suggests 

 that the inactivation of complement at 56° C. is not an irreversible 

 reaction. Brooks (1919, 1921) has confirmed these observations 

 and concludes that under proper conditions a partial return of 

 activity may occur. Just how inactivation is brought about by 

 heat is not definitely known. It is thought that a change in 

 colloidal dispersion is an important factor. 



Inactivation by Shaking. — This concept is supported by the 

 observations of Jacoby and Schiitze (1910) that prolonged shaking 

 will eventually lead to complement inactivation. This has been 

 confirmed by a number of workers. 



Anticomplementary Effects of Inorganic and Organic Com- 

 pounds. — Hektoen (1903), Manwaring (1904) and others have 

 shown that definite concentrations of various inorganic salts in- 

 hibit complement action. In 1913, Arkin reported that a number 

 of inorganic substances, as Avell as lactic acid, interfere with 

 phagocytosis and concluded that it is due to an effect upon com- 

 plement. A few 3'ears later Sherwood (1917) found that many 

 other inorganic and organic compounds will prevent the lytic 

 action of complement when present in very small concentrations. 



