Smolke:Protocols/Freezer stocks

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(New page: ==How== *Grow up overnight liquid culture *Back-dilute 20 ul into 5 ml in the morning *Grow until OD 0.7-0.9 (4-6 hrs depending on cell density and viability during back dilution) *Add 1.5...)
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==When==
==When==
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*I generally make 1 freezer stock by back-diluting from the overnight culture that I use to prep plasmids for sequencing.  This way I am certain that the freezer stock is identical to the sequenced sample.  Once the sequence has been verified, I would then go back and make the backup freezer stocks by inoculating from the first stock I made. --YC
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*I generally make 1 freezer stock by back-diluting from the overnight culture that I use to prep plasmids for sequencing.  This way I am certain that the freezer stock is identical to the sequenced sample.  Once the sequence has been verified, I would then go back and make the backup freezer stocks by inoculating from the first stock I made.  This step also serves to verify that the first stock would grow properly in liquid culture. --YC
*If I had reasons to doubt the sequence accuracy and did not wish to make a lot of freezer stocks before verifying the sequence, I would inoculate from my restreaked plate right after the sequence has been verified (the plate is generally only 2 days old at this point).  If I cannot make the freezer stocks before the plate is ~1 week old, I would transform new cells with sequenced plasmids and inoculate from the newly transformed cells.  --YC
*If I had reasons to doubt the sequence accuracy and did not wish to make a lot of freezer stocks before verifying the sequence, I would inoculate from my restreaked plate right after the sequence has been verified (the plate is generally only 2 days old at this point).  If I cannot make the freezer stocks before the plate is ~1 week old, I would transform new cells with sequenced plasmids and inoculate from the newly transformed cells.  --YC

Revision as of 17:55, 15 October 2009

How

  • Grow up overnight liquid culture
  • Back-dilute 20 ul into 5 ml in the morning
  • Grow until OD 0.7-0.9 (4-6 hrs depending on cell density and viability during back dilution)
  • Add 1.5 ml culture to 0.5 ml 60% glycerol in cryovial
  • Mix by inverting tube
  • Store at -80C
  • For every plasmid registered in lab data base, there should be 1 working stock (in the working -80C) and 2 backup stocks (in the backup -80)

When

  • I generally make 1 freezer stock by back-diluting from the overnight culture that I use to prep plasmids for sequencing. This way I am certain that the freezer stock is identical to the sequenced sample. Once the sequence has been verified, I would then go back and make the backup freezer stocks by inoculating from the first stock I made. This step also serves to verify that the first stock would grow properly in liquid culture. --YC
  • If I had reasons to doubt the sequence accuracy and did not wish to make a lot of freezer stocks before verifying the sequence, I would inoculate from my restreaked plate right after the sequence has been verified (the plate is generally only 2 days old at this point). If I cannot make the freezer stocks before the plate is ~1 week old, I would transform new cells with sequenced plasmids and inoculate from the newly transformed cells. --YC
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