GC Medium Base
With addition of supplements and hemoglobin an enriched medium for growth of fastidious bacteria.
Various workers led to the development of an agar medium for the cultivation of Neisseria sp. Carpenter et al. increased the recovery time of Neisseria sp. by reducing the agar content. The enrichment of the medium with hemoglobin and yeast concentrate also greatly improved the growth of Neisseria sp. Heated hemoglobin releases hemin which is a growth factor for fastidious microorganisms such as Haemophilus sp. Cofactors, vitamins and nicotinamide adenine dinucleotide (required by Haemophilus sp.) are present in the chemical enrichment. Chocolate Agar is composed of GC Agar Base, hemoglobin and enrichment. Thayer-Martin Agar is Chocolate Agar with the addition of vancomycin to suppress Gram positive microorganisms, colistin to suppress Gram negative microorganisms and nystatin to inhibit yeast. Anisomycin is substituted for nystatin in Martin-Lewis agar.
Appearance
Light beige to beige, homogeneous, free flowing powder.
Microbiological Analysis
Haemophilus influenza ATCC 10211: Good Growth Neisseria gonorrhoeae ATCC 9793: Good Growth Neisseria gonorrhoeae ATCC 43070: Good Growth Neisseria meningitidis ATCC 13090: Good Growth Streptococcus agalactiae ATCC 13813: Good Growth Streptococcus pneumoniae ATCC 6305: Good Growth
Directions
Dissolve 7.2grams per 100ml of ddH2O, heating with stirring until completely solubilized. Distribute and autoclave for at 121.0°C for 15 minutes. Cool to 45-50°C, mix 100ml of a 2% sterile hemoglobin solution, supplement and, if desired, selective antibiotics.
Storage and Stability
Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.
Components are shown as g/Liter
Peptic Digest of Animal Tissue | 7.5 |
Corn Starch | 1.0 |
Casein Digest Peptone | 7.5 |
Sodium Chloride | 5.0 |
Dipotassium Phosphate | 4.0 |
Monopotassium Phosphate | 1.0 |
Agar | 10.0 |