SUSPENSION MEDIUM

The suspension medium is a solution that is used to dilute the Single Colony Growth in order to obtain the Bacterial Inoculum. Typically, the suspension medium contains nutrients that will promote bacterial growth and that are used to simulate the end use conditions of the textile material.

SUSPENSION MEDIUM PREPARATION

Follow these instructions to prepare 100 ml of Suspension Medium according to test method ASTM E3160

INSTRUCTIONS

  1. In a media bottle, dilute 1/500 of TSB with deionized water.
  2. Add 0.05% of Triton X-100 and mix. To better handle the Triton, it can be previously diluted or slightly melted.
  3. Measure the pH of the obtained solution using a pH meter.
  4. Adjust the pH to a value between 6.8 and 7.2:
    1. If the solution´s pH is lower than the indicated range, the pH of the solution can be increased by adding Sodium Hydroxide (NaOH)
    2. If the solution´s pH is higher than the indicated range, the pH of the solution can be lowered by adding Hydrochloric acid (HCl).
  5. Autoclave at 121 °C for 15 minutes.

MATERIALS

  • TSB
  • Deionized water
  • Triton X-100
  • Media bottle
  • pH meter
  • Alternative: Sodium Hydroxide (NaOH) or Hydrochloric acid (HCl)
pH measurement