CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



611 



1922. Todd's Lactose Serum Agar 



Constituents : 



1. Sugar free agar 1000.0 cc, 



2. Lactose 20.0 g. 



3. Neutral red (1.0% watery 

 solution basic stain) 0.4 cc. 



4. Serum, beef 200.0 cc. 



Preparation : 



(1) Prepare sugar free agar. 



(2) Dissolve 2 and 3 in 1. (Dye strength 

 such that medium is colored.) 



(3) Tube in 7.0 to 8.0 cc. lots. 



(4) Just before use add 2.0 cc. of sterile 

 beef serum to each tube of sterile (3). 



Sterilization: Sterilize for three successive 

 days in Arnold. (Time not specified.) 



Use: Isolation and differentiation of strep- 

 tococci. Author reported that Strept, 

 pyogenes formed deep red colonies with 

 pink border. Strept. viridans (Schott- 

 miiller) formed red colonies surrounded 

 by large area of milky-like haze; Strept. 

 mucosus (Schottmiiller) pink centered 

 colonies with white border, edge irregu- 

 lar with milky-like haze. Pneumococci 

 formed red centered colonies with narrow 

 white border, smooth edge sharply de- 

 fined. Other sugars and dyes were tried 

 but this combination gave best results. 



Reference: Todd (1910 p. 74). 



1923. Harvey's Telluric Acid Serum Agar 



Constituents: 



1. Infusion agar 



2. Serum (sheep) 50.0 cc. 



3. Telluric acid (1.0% solution). 9.0 cc. 

 Preparation: (1) Mix 50 parts sterilized 



sheep serum at 45°C., 9 parts of a sterile 

 1.0% telluric acid solution at 45°C., and 

 1000 parts of melted infusion agar, cooled 

 to 45 °C., neutral red to litmus (see 

 variant (v) medium 1661 for prepara- 

 tion).* 



Sterilization: Not specified. 



Use: Enrichment medium for B. diph- 

 theriae. 



Reference: Harvey (1921-22 p. 92). 



1924. Francis' Cystine Serum Agar (Stitt) 



Constituents : 



1. Beef infusion 1000.0 cc. 



2. Peptone (1.0%) 10.0 g. 



3. Agar (1.0 or 1.5%) . . . 10.0 or 15.0 g. 



4. NaCl (0.5%) 5.0 g. 



5. Cystine (0.1%) 1.0 g. 



6. Glucose (1.0%) 10.0 g. 



7. Serum horse (5.0%) . . 50.0 cc. 

 Preparation : 



(1) Prepare beef infusion. 



(2) Dissolve 2, 3 and 4 in (1). 



(3) Adjust to pH = 7.3. 



(4) Keep this as a stock agar. 



(5) Add 0.1% cystine (or cystein hydro- 

 chloride) and 1.0% glucose to (4) 

 when ready for use. 



(6) Place in the Arnold for 15 minutes 

 in flowing steam to melt the agar, 

 and sterilize the cystine. 



(7) Cool to 45 to 50°C. and add 5.0% 

 sterile horse serum. 



(8) Tube in sterile tubes. 



(9) Slant. 



(10) Incubate for 24 hours to test 

 sterility. 

 Sterilization: Method of sterilization of 



(3) not given. Cystine sterilized in step 



(6) above. 

 Use: Cultivation of Bacterium tularense, 



gonococci and diphtheria bacilli. 

 Reference: Stitt (1923 p. 46). 



1925. Elser and Huntoon's Basal Ascitic 

 Fluid Agar 



Constituents : 



1. Distilled water 1000.0 cc. 



2. Lean beef 500.0 g. 



3. Peptone 10.0 g. 



4. NaCl 5.0 g. 



5. Agar agar 25.0 g. 



6. Litmus solution (Kubel & 

 Tiemann) 15.0 cc. 



7. Ascitic fluid 335.0 cc. 



Preparation : 



(1) Prepare basic litmus infusion agar 

 from 1, 2, 3, 4, 5, 6 and one of the 

 added nutrients in the same manner 

 exactly as given in medium 1677. 

 Use 25.0 g. agar instead of 16.0 g. 

 agar. 



(2) To the finished product which is 

 cooled to 55°C. add I its volume of 

 sterile ascitic fluid. The degree of 

 alkalinity of the ascitic fluid must be 

 previously determined and taken into 

 consideration when correcting the 

 reaction of the agar. 



Sterilization: Not specified. 



