The Best 6 Methods for Storing Yeast - Hz-Focus
When it comes to storing yeast, there are a few common methods to choose from. Here are six specific ways to store yeast, each with its own specific steps and precautions:
- 1.Freezer storage:
Step:
- 1.Prepare glycerol cryopreservation solution: Add sterile glycerol to sterile medium, usually at a ratio of 20-40%. well mixed.
2.Transfer the yeast culture to a sterile centrifuge tube.
3.Add enough glycerol freezing solution to cover the yeast culture.
4.Mix gently to make sure the glycerin is evenly distributed.
5.Seal the centrifuge tubes with cryo-tube sealers.
6.Quick freeze centrifuge tubes to -80 °C or lower.
Precautions:
- *Use aseptic technique and equipment to prevent contamination.
*Choose the right cryovials and freezing equipment to ensure fast freezing and constant low temperatures.
*Store the cryovials in a constant temperature -80 °C freezer before thawing.
2.Dry storage:
Step:
1.Cultivate yeast to logarithmic growth phase.
2.Scrape the yeast evenly with a sterile glass rod pre-cooled with sterile water.
3.Aseptically place the scraped yeast in a sterile petri dish or beaker.
4.In a fume hood or drying room, place the Petri dish or beaker under ventilated conditions to allow the yeast to dry naturally.
5.Transfer dry yeast to a sterile airtight container.
6.Store yeast in containers at low temperatures (usually 4°C).
Precautions:
*Make sure the environment in the fume hood or dry room is sterile.
*Avoid yeast contamination during drying.
*Use sterile containers for storage.
- 3.Glass tube storage:
Step:
1.Prepare sterile glass tubes.
2.Transfer the yeast culture to a sterile glass tube.
3.Close glass tubes with boiling stoppers or aluminum foil.
4.Store glass tubes at low temperature (typically 4 °C).
Precautions:
*Ensure glass tubes and closures are sterile.
*When closing the glass tube, make sure that the closure is in good contact with the glass tube to prevent contamination.
- 4.Long-term media storage:
Step:
1.Prepare specialized long-term media containing appropriate protectants and nutrients.
2.Transfer the yeast culture to long-term medium.
3.Aliquot the medium into sterile centrifuge tubes or bottles using aseptic technique.
4.Store media in centrifuge tubes or bottles at low temperature (usually 4°C).
Precautions:
*When preparing long-term media, make sure to use aseptic technique and sterile reagents.
*Check the pH and sterility of the medium before storage.
- 5.Liquid Nitrogen Freezing:
Step:
1.Prepare liquid nitrogen and special cryoprotectant solution.
2.Mix the yeast culture with an appropriate amount of cryoprotectant.
3.To snap freeze the mixture, immerse it in liquid nitrogen.
4.Transfer frozen samples to liquid nitrogen storage tanks.
Precautions:
*When handling liquid nitrogen, proper safety precautions must be taken, including wearing protective gloves and goggles.
*The use of a special cryoprotectant solution ensures the survival of the yeast at extremely low temperatures.
- 6.Subculture:
Step:
1.Periodically (usually every 1-2 weeks) transfer a portion of the yeast culture to new medium.
2.Grow yeast to logarithmic phase in new medium.
3.Repeat the above steps.
Precautions:
*Passaging yeast regularly maintains its vitality and health.
*During passaging, make sure to use sterile technique and sterile media.
Choose the storage method that suits your laboratory or individual needs and follow the steps detailed above. These methods can help you preserve your yeast long-term and maintain its vigor and purity.
