McClean: Dry Ice-Ethanol Bath

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Revision as of 18:49, 29 June 2012 by Megan N McClean (Talk | contribs)
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Contents

Overview

Dry Ice-Ethanol baths are used to rapidly cool solutions to below freezing temperatures. In the lab, we most often use this for the Bust n' Grab genomic DNA preparation protocol. This protocol was adapted from the protocol of the Malaysian Cocoa Board (no joke!). See references below.

Materials

  • Ice bucket or similar
  • Dry ice (available as pellets downstairs near the loading dock)
  • 70% (v/v) Ethanol (see notes)


Procedure

  1. Find a suitable container, such as an ice bucket, to hold the bath. Don't use something that will crack due to the extreme temperatures.
  2. Add several pieces of dry ice to the bath (see Hint #1).
  3. Carefully add the Ethanol Solution to the Dry Ice until it covers the Dry Ice in the bath (see Hint #3).
  4. After the Ethanol has cooled down, the solution will "boil" more slowly. As the "boiling" slows, add more Ethanol and / or Dry Ice as necessary.


Notes

Please feel free to post comments, questions, or improvements to this protocol. Happy to have your input!

  1. List troubleshooting tips here.
  2. You can also link to FAQs/tips provided by other sources such as the manufacturer or other websites.
  3. Anecdotal observations that might be of use to others can also be posted here.
  • Megan N McClean 18:49, 29 June 2012 (EDT) You need to be careful when handling the dry ice and especially when the bath is boiling. Wear gloves when handling the dry ice, a lab coat, and goggles (to protect your eyes in case of splashing ethanol)
  • Megan N McClean 18:49, 29 June 2012 (EDT)For general applications, use 70% (v/v) Ethanol, although other concentrations of ethanol can be used. We generally use 95% ethanol for the Bust n' Grab protocol.


Please sign your name to your note by adding '''*~~~~''': to the beginning of your tip.

References

Malaysian Cocoa Board Protocol

Contact

or instead, discuss this protocol.




1. Find a suitable container to hold the bath (see Hint #1).

2. Break the Dry Ice into easily transferable pieces (see Hint #2).

3. Add several pieces of Dry Ice to the bath.

4. Carefully add the Ethanol Solution to the Dry Ice until it covers the Dry Ice in the bath (see Hint #3).

5. After the Ethanol has cooled down, the solution will "boil" more slowly. As the "boiling" slows, add more Ethanol and / or Dry Ice as necessary.

Solutions Title | Overview | Procedure | Solutions | BioChemicals | Hints | Printable Version Ethanol Solution Prepared in ddH2O 70% (v/v) Ethanol* See Hint #4

BioReagents and Chemicals Title | Overview | Procedure | Solutions | BioChemicals | Hints | Printable Version Ethanol Dry Ice

Protocol Hints Title | Overview | Procedure | Solutions | BioChemicals | Hints | Printable Version 1. The container is usually made of stainless steel or a rubber ice bucket and not plastic. Plastics can crack, causing super cooled Ethanol to leak. Although some high performance plastics can be used as a bath, the plastic will eventually degrade and crack. Find a container with a depth that is appropriate for your application.

2. Be sure to use gloves when handling Dry Ice.

3. Be careful, the Ethanol may splatter and burn you.

4. For general applications, use 70% (v/v) Ethanol, although other concentrations of Ethanol can be used. Remember that as you lower the concentration of Ethanol in the bath, you decrease the overall temperature of the bath solution. If you use 70% Ethanol, tissue sections will freeze evenly but more slowly than if you use 100% Ethanol. When precipitating RNA, DNA, or proteins, the Ethanol Solution can contain 70% to 100% Ethanol.

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