CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



613 



ing medium to determine fermenta- 

 tion of gonococci: 



(1) Prepare sugar free infusion broth. 



(2) Add 15.0 g. peptone and 6.6 g. agar 

 to (1) and dissolve. 



(3) Adjust to reaction pH = 7.0. 



(4) Add brom-thymol-blue in suffi- 

 cient amount to give fairly deep 

 color. 



(5) Tube in 5.0 cc. lots. 



(6) Sterilize in autoclave. 



(7) To each tube of (6) add 1.0 cc. 

 ascitic fluid free from fermentable 

 substances by prolonged storage 

 in ice box. 



(8) Expose a 12.0% solution of any de- 

 sired carbohydrate to flowing 

 steam at 100°C. for 12 minutes. 



(9) Add 1.0 cc. of (8) to each tube 

 of (7). 



(10) Incubate 3 days at 37°C. to deter- 

 mine sterility. 



Author reported that with glucose, 

 medium below surface growth was 

 changed from bluish green to yel- 

 low in 18 to 48 hours. In case of 

 unf ermented sugars color remained 

 unchanged or a bluish tinge de- 

 veloped. 

 References: Plotz, Olitsky and Baehr 

 (1915 p. 10), Elser and Huntoon (1909 

 p. 407), Harvey (1921-22 pp. 83, 84, 87), 

 Torrey and Buckell (1922 p. 145). 



1926. Gilbert and Humphrey's Tellurite 

 Serum Agar 



Constituents : 



1. Beef infusion agar (1.5%). 1000.0 cc. 



2. Serum, horse (5.0%) 50.0 cc. 



3. Glucose (1.0%) 10.0 g. 



4. Potassium tellurite 1% 

 solution (0.58% on test) 



(1%) 10.0 cc. 



Preparation : 



(1) Melt sterile beef infusion agar and 

 cool to 50 °C. 



(2) Add 50.0 cc. of sterile horse serum, 

 10.0 cc. of a sterile 20% glucose 

 solution, heated to 50°C. 



(3) Weigh out 250 mgm. KiTeOs on a 

 chemical balance. Grind to a very 

 fine powder. 



(4) Add about 10.0 cc. of water. Mix 

 well. 



(5) Allow the undissolved portion to 

 settle out and pour off the super- 

 natant fluid. 



(6) Add more water to the residue and 

 grind again. Combine the two 

 portions. 



(7) Rinse the mortar with the remainder 

 of the 25.0 cc. of water. 



(8) Filter thru paper. 



(9) Heat sterile (8) to 50°C. and add 

 to (2). 



(10) Mix (9) thoroly and insert in a sterile 

 siphon. 



(11) Dispense in Petri dishes. 



(12) Incubate the plates to test sterility. 

 Sterilization: Method of sterilization of 



agar, serum or glucose not given. Steri- 

 lize the potassium tellurite solution by 

 filtration thru a Mandler. 



Use : Isolation of diphtheria bacilli. Diph- 

 theria colonies white, or white about the 

 periphery with grey centers. Staphylo- 

 cocci are black. 



Reference: Gilbert and Humphreys (1926 

 p. 149). 



1927. Scholtz's Ascitic Fluid Agar 



Constituents : 



1. Infusion agar. 



2. Ascitic fluid. 

 Preparation : 



(1) Prepare infusion agar. 



(2) Mix (1) with ascitic fluid (pericardic 

 or hydrocelenic fluid may be used) 

 in the ratio of 3 to 1. 



Sterilization: Not specified. 



Use: Cultivation of gonococci. 



Variants : 



(a) Swartz and Davis used the following 

 medium to cultivate gonococci. 

 Have the medium at body tempera- 

 ture when inoculating. Following 

 inoculation hold the tubes horizon- 

 tally so that the agar slant is upper- 

 most. Holding the tubes by the 

 butt, pass the tubes thru the flame 

 three times longitudinally and cork 

 quickly. 



(1) Prepare a 2.0% beef (or veal) infu- 

 sion agar in the usual manner. 



(2) Adjust (1) to pH 7.6 (pH 7.4 after 

 autoclaving) and sterilize in the 

 autoclave. 



(3) Mix one part sterile ascitic fluid 



