R24. Gel Diffusion Agar. 1.2% NaCl 8.5 g Sodium barbital 8.0 g Merthiolate (crystalline) 0.1 g Noble special agar (Difco) 12.0 g Distilled water 1 liter
Dissolve NaCl, sodium barbital, and merthiolate in 900 ml distilled water. Adjust pH to 7.4 with 1 N HCl and/or 1 N NaOH. Bring volume to l liter. Add Noble agar. Melt agar mixture in Arnold steamer. Filter in steamer, while hot, through 2 layers of analytical grade filter paper (e.g., No. 588, Schleicher and Schuell or equivalent). Dispense in small (15-25 ml) portions into 4 oz prescription bottles. Do not remelt more than twice.
R25. Gel-Phosphate Buffer Gelatin 2 g Na2HPO4 4 g Distilled water 1 liter
Use gentle heat to dissolve ingredients. Sterilize 20 min at 121°C. Final pH, 6.2.
R26. Giemsa Stain Giemsa powder 1 g Glycerol 66 ml Methanol (absolute) 66 ml Distilled stain in glycerol by heating 1.5-2.0 h at 55-60°C. Add