​Step 4 –  Prepare larger GEL bag and add Aquagenx GEL powder (see video)

  • Wear disposable, thin plastic gloves.
  • Label larger GEL bag or attach barcode asset tag to bag.
  • Hold the top of the bag with both hands, pull apart the reclosable seal and shake bag to fully open the bag.
  • Open GEL packet with scissors and pour GEL powder into open bag. Gently tilt and shift the bag to move the powder out of the corners and to the center and bottom of the bag as much as possible.

Step 5 –  Pour sample with dissolved EC medium from Thio-Bag into Aquagenx GEL bag (see video)

  • Pour entire sample from Thio-Bag into fully opened GEL bag, but do not seal the bag yet. As soon as the sample is added, squeeze the mixture with your fingers for a few seconds to begin to dissolve powder. Next, lie the GEL bag on flat surface with the bag opening slightly elevated so the mixture will not leak out of the bag.
  • Firmly and rapidly use your hand to press the mixture toward the bottom of the bag. You can massage and press clumps of powder to help them dissolve. Continue until mixture becomes thick and gelatinous. Next, use the palm of hand to spread and press the mixture toward the top of the bag. When the mixture is about 2/3 up the length of the bag, seal the bag shut.
  • Continue spreading and pressing the mixture throughout the bag to achieve as uniform a thickness as possible.


PDF – Preliminary Draft GEL CFU Instructions for Use Drinking Water, April 2021