Amies Transport Medium | Principle | Preparation
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Ⅰ. Overview
Amies medium is a semi-solid transport medium recommended for qualitative procedures of collection, transportation and preservation of clinical specimens as well as for long-term storage in the freezer. It is formulated to maintain the viability of microorganisms without significantly increasing growth.
The Amies transport medium, introduced by Stuart et al. in 1954, is a modification of Stuart transport medium, produced by replacing glycerophosphate with inorganic phosphate buffer and adding charcoal to the medium
The Amies formulation may contain charcoal, which has been shown to increase the survival of gonococci in the transport medium.
Amies Transport Medium
Ⅱ. Preparation / composition
Suspend the components, dehydrated powder, in water (20g in 1000ml of purified/distilled water). Bring to a boil and completely dissolve the medium.
Spoon into small screw-top bottles, stirring meanwhile to keep the charcoal in even suspension. sterilize in an autoclave at 121°C for 15 minutes.
Invert the bottles while cooling to evenly distribute the charcoal. Store in a cool place.
Amies transport medium composition |
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|---|---|---|---|
| Ingredients | gram/litre | Ingredients | gram/litre |
| Sodium Chloride | 3g | Magnesium Chloride | 0.1g |
| Potassium Chloride. | 0.2g | Dipotassium phosphate | 0.2g |
| Disodium Phosphate | 1.15g | Agar | 4,0g |
| Calcium Chloride | 0.1g | Demineralised water | 1000.0ml |
| Sodium Thioglycolate | 1.0 | Coal (optional) | 10.0g |
Ⅲ. Principle
The transport medium should be non-nutritive, semi-solid and reducing and should be able to hinder self-destructive enzymatic reactions.
Amies Transport Medium provides a reduced environment due to the presence of sodium thioglycolate and a small amount of agar.
Charcoal helps neutralize materials that are toxic to susceptible pathogens like Neisseria gonorrhoeae.
Salts aid in the survival of gonococcal cells and also control the permeability of bacterial cells.
The phosphate buffer maintains the pH of the medium.
Ⅴ. Instructions for use
Insert the seeded sterile swabs into the upper third of the transport medium inside the transport container.
Break the protruding part of the swab and screw it tight.
Send to lab within 24 hours for culture analysis.
Samples can be refrigerated until ready to ship.