158 LABORATORY COURSE IN SERUM STUDY 



HwEMAGGLUTINATIVE EFFECT OF RlCIN 



Ricin agglutinates the cells of all species to a greater or lesser 

 degree. The presence of serum in any considerable quantity 

 interferes with the reaction. Specific antitoxic sera (which are 

 difficult to prepare) neutralize in high dilutions not only the 

 poisonous but also the agglutinative component of ricin. 



Incubate one hour. 



Make all volumes equal by adding saline. 

 Observe hsemagglutination. 



Each student requires : 

 5.0 c.c. guinea pig cells 5 %. 

 0.5 c.c. guinea pig serum. 

 7.0 c.c. sheep cells. 

 8.0 c.c. sheep serum. 

 1.0 c.c. lecithin diluted 1-2000. 

 1.0 c.c. cobra venom diluted 1-1000. 

 4.0 c.c. ricin diluted 1-1000. 

 Salt solution. 



LESSON XXV 



DETERMINATION OF ANTITRYPTIC ACTIVITY OF BLOOD 



SERUM 



NORMAL blood contains a trypsin-like ferment. This enzyme 

 digests protein in neutral or weakly alkaline solution, with the 

 formation of amino-acids. Under ordinary conditions its action 

 is inhibited by the presence of substances in serum which have 

 been shown by Jobling and Peterson to be compounds of unsat- 

 urated fatty acids. 



This antitryptic activity is greatly increased in cachectic 



