THE STUDY OF OBLIGATELY ANAEROBIC BACTERIA 11143-9 



Advantages: Anaerobiosis is attained quickly. It is a useful method for single 

 p'ate culture. Since each plate is a single unit, observations may be made at any 

 time and any particular plate of a series may be opened when visual inspection reveals 

 growth to be at the desired stage. Recommended for clinical laboratory technicians 

 seeking a quick method of purification of possible pathogenic types. Disadvantages: 

 Some time is required to prepare the individual dishes; therefore laboratories doing 

 a great deal of routine work may desire to use instead some of the anaerobic jars. 

 Special plates must be purchased. 



Tube Culture 

 Method A 



Materials: (1) Agar slant of suitable anaerobic medium; (2) 

 pyrogallic acid crystals; (3) 10% aqueous NaOH; (4) rubber stopper. 



Method: Inoculate agar slant with anaerobic organism or from 

 sample to be cultured. Flame mouth of tube before replacing plug. 

 Cut off the end of the cotton plug which extends beyond the mouth 

 of the tube and push the remaining portion into the tube for a dis- 

 tance of about 2 cm. Fill this space with pyrogallic acid crystals 

 and pour 2 ml. of 10% NaOH upon the crystals. Immediately 

 insert rubber stopper and invert tube in such a fashion that the water 

 of condensation does not run across the slant. Incubate tube in 

 inverted position. 



Method B 



Materials for method of Griffin (1932) : (1) Two test tubes with 

 approximately ^i inch diameter (one empty and the other containing 

 a liquid or slant culture of the anaerobe); (2) two one-holed rubber 

 stoppers to fit tubes; (3) short piece of small diameter rubber tubing; 

 (4) two short pieces of glass tubing of diameter to fit tightly in holes 

 of rubber stoppers; (5) small glass vial; (6) dry pyrogallic acid; 

 (7) strong aqueous NaOH. 



Method: Put a column of pyrogallic acid, approximately 1}^ 

 inches high, in the bottom of the empty tube. Stand empty vial 

 in this acid. With pipette, fill vial two thirds full of NaOH solution. 

 Fashion a connecting unit from the rubber stoppers, and rubber and 

 glass tubing. Insert one of the stoppers in the tube with the chemi- 

 cals. Push down cotton plug in culture tube to a level one inch 

 above the medium. Insert second stopper in this tube. Tilt 

 tube containing chemicals sufficiently to allow NaOH solution to 

 spill over the acid. 



Advantages: Good method for single tube culture. If a supply of chemicals is 

 at hand, it is useful as an emergency system, when the special equipment required 

 by other systems is not available. Disadvantages: Not suitable for large numbers 

 of cultures, or, at least, such use would be more time consuming than other methods. 



CHROMIUM AND SULFURIC ACID METHOD 



Rosenthal (1937) introduced a new system for creating an anaero- 

 bic environment using the reaction of H2SO4 on powdered chromium 

 to release hydrogen. This flushes out the oxygen by replacing the 



