AGGLUTINATION TEST FOR DIAGNOSIS i fele) 
a slide, and after it has become well mixed add a loopful of 
it to a similar quantity of a fresh bouillon culture and examine 
it immediately in a hanging drop. 
Complete and hand in all laboratory notes. 
165. Securing blood for the agglutination test. (@) Prepa- 
ration of dried blood. Prick the finger or the lobe of the ear 
Gf in a lower animal, the shaved ear is a good place) suffi- 
ciently deep to procure a drop of blood. Place it on a slide 
by means of a platinum loop and allow it to dry. 
(6) Fresh blood. Procure a drop of blood as in (a); add 
to it ro drops of water on a glass slide or in a small test tube. 
Stir until the blood is dissolved. One loopful of this mixed 
with a similar quantity of the bouillon will give a dilution of 
I to 20. 
(¢) Serum. From a similar but deeper prick, or by draw- 
ing a few drops of blood from a vein with a hypodermic 
needle, secure a few drops of blood. Place them in the 
bottom of a small, short, sterile tube and allow the serum to 
ooze out. It is important to separate the blood from the tube 
by means of a sterile wire. If retained for any length of time 
before making the test, the serum must be kept in a cool place. 
Experimentally, it is easily obtained by immunizing a guinea 
pig and then drawing the desired amount of blood from a vein. 
Blood serum may be obtained by filling a small (capillary) 
glass tube with the fresh blood, sealing it, and allowing it to 
stand until the serum collects on the top, when the tube may 
be broken and the serum drawn off with a fine-pointed pipette. 
