Effect of Solid Surface Vitrifi cation on Viability and Morphology of Canine Cumulus-Oocyte Complex

Abstract

The effects of a solid surface vitrifi cation (SSV) method were determined on the viability and morphology of canine cumulus-oocyte complexes (COCs). All COCs from each dog were randomly divided into fi ve groups. Every group except the control (group 1) was equilibrated and separately introduced into a different recipe for the vitrifi cation medium. A vitrifi cation medium consisting of tissue culture medium (TCM) 199, supplemented with 0.5 M trehalose, 1.5 M ethylene glycol and 20% fetal bovine serum was used for COCs for groups 2 and 4, whereas a vitrifi cation medium consisting of TCM 199, supplemented with 0.5 M trehalose, 3 M ethylene glycol and 20% fetal bovine serum was used for groups 3 and 5. Only the COCs from groups 4 and 5 were vitrifi ed with the solid surface method. The survival rates of non-vitrifi ed and vitrifi ed COCs were not signifi cantly different. Morphological alterations including shrinkage, disrupted oolemma, cumulus cell damage and cytoplasmic vacuolization were common features found in treatment groups. The percentages of COCs with each type of damage were not different. However, cumulus cells appeared to be the structure most affected by the SSV method.