GC Agar

GC Agar

SKU: KM0016 Category:

GC Agar when used with blood and other enrichment is for the isolation of Neisseria gonorrhoeae but is also capable of supporting the growth of most fastidious micro-organisms. This medium is based on the modified formulation described by Thayer and Martin that was based on the original formulation stated by Johnson.
Enrichment is usually attained using lysed blood but haemoglobin powder or chocolated blood are suitable alternatives. Additional enrichment can be provided by the addition of Suplex supplement (BM0478) which consists of yeast extract and glucose.
Selective variants of GC Agar can be prepared through the addition of various selective supplements such as VCAT (LS0002) or LCAT (LS0001). These supplements will suppress most of the background flora likely to be present in specimen and will restrict the swarming of Proteus spp.
The peptone is the source of the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance in the medium. Starch is present to absorb toxic metabolites and phosphate buffers prevent pH changes during incubation.

Related Supplements :
BM0478 Suplex, LS0001 GC LCAT Selective Supplement, LS0002 GC VCAT Selective Supplement

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Neisseria gonorrhoeae (with LCAT selective supplement added) ATCC 43069 Growth, grey colonies
Neiserria gonoeehoeae (with LCAT selective supplement added) ATCC 43070 Growth, grey colonies
Neisseria meningitides (with LCAT selective supplement added) ATCC 13090 Growth, grey colonies
Escherichia coli (with LCAT selective supplement added) ATCC 25922 Inhibited
Staphylococcus epidermidis (with LCAT selective supplement added) ATCC 12228 Inhibited
Proteus mirabilis (with LCAT selective supplement added) ATCC 29906 Inhibited
Neisseria sicca (with LCAT selective supplement added) ATCC 9913 Inhibited
Candida albicans (with LCAT selective supplement added) ATCC 60193 Inhibited
Neisseria gonorrhoeae (with 7% chocolated blood) ATCC 43069 Growth, grey colonies
Haemophilus influenzae (with 7% chocolated blood) ATCC 10211 Growth, grey colonies



Peptone 15.0
Starch 1.0
Sodium chloride 5.0
Di-potassium hydrogen phosphate 4.0
Potassium di-hydrogen phosphate 1.0
Agar 10.0
Total 36.0
*Adjusted/supplemented as required to meet performance requirements


Suspend 36g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes with frequent stirring to completely dissolve the medium. Cool to 45-50°C. After cooling aseptically add the required type and concentration of blood and selective supplements that are required to manufacture the chosen GC Agar formulation. Allow to mix and aseptically dispense into appropriate sterile containers.