MATERIAL FROM THE LIVING SUBJECT 257 
into sterile capillary pipettes; if in considerable quantity, removed to 
test-tubes or flasks, and inoculated as soon as practicable into suitable 
media. Anaerobic cultures in media containing blood frequently are 
very important. 
MATERIAL FROM THE LIVING SUBJECT. 
Blood Cultures.— The organisms of septicemia may be numerous 
or few in number in the blood stream— furthermore, they may be 
associated with specific lysins and agglutinins, as occasionally hap- 
pens in typhoid fever. For these various reasons, experience has 
shown that from 5 to 15 cc. of blood, drawn aseptically, should be 
discharged at once with appropriate precautions into at least 100 
cc. of 0.1 per cent meat infusion glucose broth, ^ and evenly distrib- 
uted by careful agitation. The degree of dilution attained practically 
renders lytic action and agglutination ineffective; the enrichment of 
the medium by the relatively large proportion of blood creates a very 
favorable environment for the development of the organisms. 
Technique of Blood Culture. — 1 . Apparatus. —An all-glass syringe with 
a platinum-iridium needle of moderately large bore is sterilized in the 
autoclave, preferably enclosed in a large test-tube. A syringe cannot 
be sterilized for bacterial purposes by boiling in water. 
As an alternate apparatus, a 250 cc. Ehrlenmeyer flask fitted with 
a rubber stopper containing two glass tubes bent at right angles may 
be used. The flask contains 100 cc. of 0.1 glucose meat infusion 
broth. One tube is connected with a platinum-iridium needle by a 
short length of rubber tubing, and the needle is protected during 
sterilization by a small test-tube slipped over it and extending its 
full length. The test-tube is removed when the blood is to be taken. 
The other tube is protected by a short length of rubber tubing con- 
taining a small filter of absorbent cotton. Suction is applied through 
the latter tube. It will be seen that blood may be drawn directly 
into the broth in this apparatus, and in practice it has been found 
convenient to replace the rubber stopper with a sterile cotton plug 
after the blood is mixed with the media. 
2. CoUection of Blood. —The skin over the median basilic vein is 
cleansed with green soap and alcohol, dried and sterilized by the 
application of recently prepared tincture of iodine, which is allowed 
to act for two to three minutes. Then the point of the needle is 
gently inserted into the vein (which may be made prominent by 
gentle pressure with a tourniquet applied to the arm above the elbow) 
and from 5 to 20 cc. of blood withdrawn. This is introduced at 
once into broth, as outlined above.- 
1 See Media. 
- Occasionally circumstances arise wiiicli make it necessary to send the blood to a 
distance for examination; mixing the blood with an equal volume of glycerin bile (1 
part glycerin, 10 parts ox bile; sterilize in autoclave) is said to be an efficient method 
for preserving the bacterial content of blood practically unchanged for several hours. 
17 
