202 DIFCO MANUAL 



For best grovs^h of anaerobes and most aerobes, A C Medium should be dis- 

 tributed in tubes or flasks to give a depth of at least 70 mm. of medium. For 

 obligately aerobic bacteria shallower layers permitting aeration of the substrate 

 are desirable. 



To rehydrate the medium, suspend 35 grams of Bacto-A G Medium in 1000 

 ml. of cold distilled water and heat to boiling to dissolve the medium completely. 

 Distribute in tubes or bottles to give the desired depth of medium and sterilize 

 in the autoclave for 15 minutes at 15 pounds pressure (121°C.). If the medium 

 is not used the same day it is prepared and sterilized, it is advisable to place it in 

 flowing steam or in a boiling water bath to drive off dissolved gases and then cool 

 before inoculating. The final reaction of the medium will be pH 7.3. 



One pound of Bacto-A G Medium will make 13 liters of medium. 



1 Paper read at New York Meeting Am. Pub. * Pub. Health Reports, 60:789:1945. 



Health Assoc, 1944. ^Personal Communication, 1947. 



' J. Bact., 62:349:1951. ^ Pub. Health Reports, Sup. No. 207, June, 1948. 



«J. Bact., 45:309:1943- ^J- Bact., 59:401:1950. 



BACTO 



A G BROTH (B317) 



DEHYDRATED 



Bacto-Beef Extract 3 g. 



Bacto- Yeast Extract 3 g. 



Bacto-Malt Extract 3 g. 



Proteose Peptone No. 3, Difco 20 g. 



Bacto-Dextrose 5 g. 



Ascorbic Acid 0.2 g. 



Bacto-A C Broth is particularly suitable for use as a sterility test broth in the 

 detection of obligately aerobic contaminants in biologicals and other products. 

 Sterility tests on materials containing mercurial preservative should be made in 

 Bacto-Fluid Thiogly collate Medium, as discussed on page 195. 



Bacto-A G Broth is recommended as a general culture m_edium for the propa- 

 gation of pathogenic and saprophytic microorganisms. It has the same formula 

 as Bacto-A G Medium, as discussed on page 201, except that the small amount of 

 agar has been omitted. This medium with the addition of 0.85 per cent sodium 

 chloride and 1.8 to 2.5 per cent Bacto-Agar was reported by Schneiter, Dunn and 

 Caminita^ to be a superior medium for bacteriological examination of air, espe- 

 cially for recovery of streptococci. 



To rehydrate the medium, dissolve 34 grams of Bacto-A G Broth in 1000 ml. 

 of distilled water. Distribute in tubes or other suitable containers and sterilize in 

 the autoclave for 15 minutes at 15 pounds pressure (121°G.). The final reaction 

 of the medium will be pH 7.2. 



One pound of Bacto-A G Broth will make 13 liters of medium. 

 1 Pub. Health Reports, 60:789:1945. 



BACTO 



MALT EXTRACT BROTH 



DEHYDRATED 



Bacto-Malt Extract Broth is recommended as a sterility test medium for the 

 detection of yeasts and molds. This acid medium supports early and luxuriant 



