TECHNIC FOR PREPARING BACTERIAL VACCINES 



219 



to insure thorough mixing, and 0.1 c.c. of a 1:100 



added to each cubic centimeter of vaccine as a 

 preservative against chance contamination. Thus, 

 in the foregoing example, 3 c.c. of the diluted 

 phenol would be added. The amount of stock 

 vaccine is estimated or measured, 0.5 per cent, 

 phenol is added, and the vaccine stored in a 

 sterile container in the refrigerator, being first 

 properly labeled with the patient's name, the 

 date, and the number of bacteria per cubic centi- 

 meter. 



The vaccine may now be placed in a sterile 

 vaccine bottle, fitted with a sterile rubber cap, 

 and properly labeled (Fig. 64). When it is to be 

 administered, the cap is 

 touched with tincture of iodin, 

 the needle plunged through the 

 cap, and a dose withdrawn with 

 a sterile syringe. The punc- 

 ture in the cap is then sealed 

 with a drop of flexible collo- 

 dion. This method is inex- 

 pensive, and with proper care 

 is quite satisfactory, especially 

 for stock vaccines. 



Another and probably 

 better method, especially for 

 autogenous vaccines, consists 

 in tubing each dose in separate 

 sterile ampules (Fig. 65), which 

 are then sealed in the flame. When the vaccine 

 is to be administered, the ampule is well shaken, 

 the neck broken in a towel, and the contents 

 aspirated into a sterile syringe. These ampules 

 may be purchased ready for use or be made in 

 the laboratory, using 6 mm. soft glass tubing 

 (Fig. 6). For pipeting a vaccine into ampules the 

 special automatic pipet shown in the illustration 

 (Fig. 66) is quite convenient. As a rule, vac- 

 cines should be preserved in a cool place, such as 



dilution of phenol is 



FIG. 65. A SMALL 



VACCINE AMPULE. 



Capacity 1 c.c. 



FIG. 66. COMER'S 

 AUTOMATIC PIPET. 

 (Steele Glass Co., 

 Philadelphia.) 



The inner tube to 

 the tip of the pipet 

 holds exactly 1 c.c. If 

 the rubber teat raises 

 too much fluid, the 

 excess is received in the 

 glass reservoir; when 

 too much fluid accumu- 

 lates in this, it may be 

 emptied by turning the 

 point of the inner tube 

 downward and ejecting 

 the fluid by pressure on 

 the teat. 



a refrigerator. 



