Amies Transport Medium is a specialized solution designed for the collection, transport, and preservation of specimens for the detection of pathogenic bacteria. This medium provides essential elements such as sodium thioglycolate, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, disodium hydrogen phosphate, and potassium dihydrogen phosphate to maintain bacterial viability. The addition of agar ensures a solidified gel consistency.
When sterilized at 121°C, the medium achieves an optimal pH of 7.2–7.4 at 25°C. This guide explains the formulation, preparation, and application of Amies Transport Medium for laboratory use.
Medium Composition (per Liter):
- Sodium Chloride: 3.0 g
- Potassium Dihydrogen Phosphate: 0.2 g
- Disodium Hydrogen Phosphate: 1.1 g
- Potassium Chloride: 0.2 g
- Magnesium Chloride: 0.1 g
- Sodium Thioglycolate: 1.0 g
- Calcium Chloride: 0.1 g
- Agar: 7.5 g
Preparation and Usage
For Powdered Medium:
- Reagent Preparation: Weigh 13.25 g of powdered medium and dissolve in 1,000 ml of distilled water. Heat until dissolved, dispense into test tubes, and sterilize at 121°C for 15 minutes. Allow to cool to room temperature for solidification before use.
- Conditions: pH must be 7.2–7.4; transport temperature should be 5–25°C within 24 ± 2 hours.
- Calibration: No calibration required.
- Quality Control: Follow strict aseptic techniques.
- Sample Transport: This medium is intended solely for sample transportation.
For Ready-to-Use Tubes:
- Open the packaging before sampling.
- Extract the swab and transport tube.
- Collect the sample from the designated site.
- Insert the swab into the transport medium.
- Label the sample with relevant details.
- Transport the tube to the laboratory for testing.
- Perform direct streaking and separation.
Results Observation
After 48 hours of aerobic incubation at 20–25°C, the following control strains should exhibit positive growth:
| Strain | ATCC Number | Growth Performance | Results |
|---|---|---|---|
| Escherichia coli | ATCC25922 | +++ | Growth Good |
| Shigella flexneri | ATCC12022 | +++ | Growth Good |
| Salmonella typhimurium | ATCC14028 | +++ | Growth Good |
| Staphylococcus aureus | ATCC25923 | +++ | Growth Good |
| Streptococcus pyogenes | ATCC19615 | +++ | Growth Good |
| Streptococcus hemolyticus | ATCC13813 | +++ | Growth Good |
Precautions
- For in vitro diagnostic use only.
- Disinfect used medium after use.
- Use only by trained personnel.
- Wear gloves and masks for protection during use.
- Samples should be processed within 24 ± 2 hours for optimal bacterial recovery.
- Do not use expired products.
