X-Message-Number: 9974
Date: Sat, 4 Jul 1998 02:27:23 -0700 (PDT)
From: Doug Skrecky <>
Subject: cooling rate

Authors
  Luvoni GC.  Pellizzari P.  Battocchio M.
Institution
  Institute of Obstetrics and Gynecology, Faculty of Veterinary Medicine,
  University of Milan, Italy.
Title
  Effects of slow and ultrarapid freezing on morphology and resumption of
  meiosis in immature cat oocytes.
Source
  Journal of Reproduction & Fertility - Supplement.  51:93-8, 1997.
Abstract
  This study examined the ability of immature cat oocytes to survive after
  cryopreservation by evaluating their subsequent development following
  maturation in vitro. The effect of slow and ultrarapid freezing using one of
  two cryoprotectants dimethylsulphoxide (DMSO) or 1,2-propanediol (PROH) at
  different concentrations (1.5 or 3.0 mol-1) and the slow freezing with the
  cryoprotectant ethylene glycol (EG 1.5 mol l-1 and 3.0 mol l-1) were tested.
  Morphology, resumption of meiosis and metaphase II rates of oocytes were
  recorded after thawing. Freshly collected oocytes were used as controls.
  Results indicate that immature cat oocytes can survive, resume meiosis and
  achieve metaphase II in vitro after freezing. The highest rates of resumption
  of meiosis and metaphase II were achieved with slow freezing and 1.5 mol DMSO
  or EG l-1 (DMSO: 47.4%, 18/38 and 23.7%, 9/38 and EG: 52%, 13/25 and 20%,
  5/25, respectively). The ultrarapid procedure did not result in resumption of
  meiosis in vitro, despite intact morphology of the oocytes after thawing.
  These results suggest that morphology of oocytes after freezing and thawing
  has no predictive value for their ability to resume meiosis.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9974