lyophilizing cultures

R. Jayakumar jakku at
Sat Jul 7 13:40:45 EST 2001

  I am trying to lyophilize my bacterial cultures for some time now using a
virtis lyophilizer and the flame sealing utility which also we have.
Somebody told me that I should add 2% milk powder to the culture and then do
the lyophilization.  is that true?  Anyway, I am facing problems.  I first
grow the culture in 2 ml LB or NB or .... overnight, and then add sterile
10X stock of milk powder solution to a final conc. of 2%. I take 0.5 ml of
this in the virtis long stemmed sterile glass ampule, close it with cotton
and freeze it quickly in -70C.  Then I fix it to one of the vacuum outlets
on the lyophilizer and start the drying process. I faced several problems.
  1.  The culture somehow thaws and starts bubbling badly.. virtually all
the culture in some tubes gets sucked upwards and absorbs into the cotton
during drying due to the vacuum. I am losing the cultures substantially.
How do I prevent this?
   2. Can I add anything else other than milk powder to the solution?  I
need some real quick replies for this... since i need to do and finish it by
   thank you

R. Jayakumar
Dept. of Molecular Microbiology,
School of Biotechnology,
Madurai Kamaraj University,
Madurai - 625021. India.
Tel: +91-452-859141(night hours), +91-452-858471 (Working hours - ask to
connect to 374)
Efax: (603)-688-4665
Email: jakku at, (send a copy to jakku at ....just in
Science is constructed of facts like a house is of bricks, but a mere
accumulation of facts does not make science nor does a pile of bricks a
-Henri Poincare


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