THAWING

Thawing brings frozen samples, such as glycerol stocks or a plasmid library, up to a usable temperature without damaging them. Thawing slowly on ice keeps cells alive and stops DNA or proteins from breaking down.

WHAT YOU NEED?

• Frozen sample from the −80°C freezer

• Ice bucket with ice

• Gloves and a tube rack

STEPS

1. Fill an ice bucket before taking anything out of the freezer.

2. Take out only the tubes you need and close the freezer quickly.

3. Place the tubes in the ice and let them thaw slowly, keeping the lids closed.

4. Once thawed, flick or invert gently to mix. Do not vortex cells.

5. Take what you need using sterile technique.

6. Return any leftover stock to the −80°C freezer as soon as possible.

TIPS

• Avoid repeated freeze–thaw cycles; they kill cells. Split stocks into small aliquots if you will use them often.

• Never thaw stocks at room temperature or in your hand.

• Keep the tube on ice the whole time you are working with it.