X-Message-Number: 11995
Date: Wed, 23 Jun 1999 13:04:11 -0700 (PDT)
From: Doug Skrecky <>
Subject: lyophilization is critical for refrigerated storage

Authors
  Brown Thomas J.  Duewer DL.  Kline MC.  Sharpless KE.
Institution
  Analytical Chemistry Division, National Institute of Standards and
  Technology, Gaithersburg, MD 20899, USA.
  
Title
  The stability of retinol,
  alpha-tocopherol, trans-lycopene, and trans-beta-carotene in liquid-frozen
  and lyophilized serum.
Source
  Clinica Chimica Acta.  276(1):75-87, 1998 Aug 10.
Abstract
  The concentrations of retinol,
  alpha-tocopherol, and trans-beta-carotene in lyophilized serum stored at -25
  degrees C and -80 degrees C have been monitored for 10 years.
  There was no evidence of degradation of any of
  these compounds over the 10-year period.
  Retinol, alpha-tocopherol, and trans-beta-carotene were less
  stable at -25 degrees C in liquid-frozen serum than they
  were in lyophilized serum. At -80 degrees C, trans-beta-carotene levels were
  stable for up to 3 years of storage in liquid-frozen serum. Both
  retinol and alpha-tocopherol appeared stable in
  liquid-frozen serum for at least 5 years at -80 degrees C.
  The effect of repeated freeze/thaw cycles on
  retinol, alpha-tocopherol, trans-lycopene, and
  trans-beta-carotene in liquid-frozen and reconstituted lyophilized serum both
  stored at -20 degrees C was also studied. Retinol,
  alpha-tocopherol, trans-lycopene, and trans-beta-carotene in reconstituted
  lyophilized serum stored at -20 degrees C were stable for at least 3 days
  with minimal (< 5) freeze/thaw cycles.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11995