X-Message-Number: 12107
Date: Sat, 10 Jul 1999 08:48:09 -0700 (PDT)
From: Doug Skrecky <>
Subject: "new" vitrification solution

  Valdez CA.  Abas Mazni O.  Takahashi Y.  Fujikawa S.  Kanagawa H.
  Department of Theriogenology, Faculty of Veterinary Medicine, Hokkaido
  University, Sapporo, Japan.
  Successful cryopreservation of mouse blastocysts using a new vitrification
  Journal of Reproduction & Fertility.  96(2):793-802, 1992 Nov.
  Mouse blastocysts were exposed to solutions containing four concentrations
  (10, 20, 30 and 40% v/v) of six permeating cryoprotectants (glycerol,
  ethylene glycol, propylene glycol, dimethyl
  sulfoxide, 1,3-butanediol and 2,3-butanediol) in
  phosphate-buffered saline (PBS) with calf serum (CS) at room temperature
  (20-22 degrees C). Blastocysts were exposed to these solutions for various
  periods, diluted into PBS plus CS with or without 1 mol trehalose l-1
  solution and their subsequent survival in vitro was examined. Two-way anova
  showed a significant interaction (P < 0.01) between cryoprotectant type,
  concentration of cryoprotectant and method of dilution. However, no
  significant interaction was observed between cryoprotectant type and duration
  of exposure. Results suggest that cryoprotectant-induced injury to nonfrozen
  blastocysts is variable and depends on the cryoprotectant used. On the basis
  of toxicity assays, ethylene glycol was the least harmful and was combined
  with dimethyl sulfoxide and 1,3-butanediol
  to produce a new vitrification solution. Mouse blastocysts were successfully
  cryopreserved using a vitrification solution (designated as VSv) consisting
  of 20% ethylene glycol, 20% dimethyl
  sulfoxide and 10% 1,3-butanediol (v/v). Embryos were
  equilibrated in two steps, first in an equilibration solution (designated as
  ESv: 10% ethylene glycol, 10% dimethyl
  sulfoxide and 5% 1,3-butanediol; v/v) and then to VSv or
  one-step in VSv at different exposure times at room temperature, and then
  vitrified by direct plunging into liquid nitrogen. High developmental rates
  were obtained in vitro when the embryos were exposed to ESv and VSv for 3 and
  0.5 min, respectively (96.2%) or exposed to VSv for 0.5 min (95.4%).
  Prolonged exposure time proved detrimental to subsequent embryo development
  in vitro. When vitrified warmed embryos were transferred immediately to
  pseudopregnant recipients, the rate of development to normal fetuses did not
  significantly differ from that of the nonvitrified control (two-step, 54.2
  and one-step, 45.0 versus 60.0%, P > 0.05). These results suggest that the
  simple vitrification solution described in this study is effective for the
  cryopreservation of mouse blastocysts.

  Additional note by poster:
    The prolonged exposure results mean this solution is likely useless
  for whole organ vitrification.

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