Be sure to use aseptic technique, described in more detail below, while conducting all aspects of this preparation. Pre-made agar plates can be purchased from a variety of vendors, or made on your own (see recipe below).
- Collect the number of agar plates you will need, and label each with a sharpie marker to include your initials, date, ferment being plated, and the phrase “DO NOT OPEN”.
- Set up 2 tubes per ferment you plan on testing, and label each tube accordingly.
- Tube A will be prepared at room temperature.
- Tube B will be boiled before plating.
- For each ferment being tested, transfer approximately 1ml of fermentation liquid to Tube A, and 1ml of ferment liquid to Tube B.
- Each time you go to transfer materials from the source to a tube, or from tube to tube, be sure that the transferring instrument is sanitized each time, or use a new sterile transfer pipette.
- Keep set A tubes on the countertop. Boil sample set B for 10 minutes by placing the tubes in boiling water or a heat block set to 100 °C.
- by boiling the ferment, you are presumably killing all of the microbes present.
- Pour the liquid in each tube onto the correspondingly labeled agar plate.
- Spread the liquid culture evenly around the agar plate using a sterile swab or cotton swab.
- Return the lid to the agar plate, and allow the liquid to dry.
- Turn the plate upside down (so that the agar side is up) and leave on the countertop to grow for 1-4 days.
- Record observations, room temperature, and other factors that may be relevant.
- At the end of the growth period, compare the difference between Tube Set A (unboiled) and Tube Set B (boiled).
Do you notice a difference between the unboiled and boiled ferments after plating?