Evaluation of meiotic spindles in thawed oocytes after vitrification using polarized light microscopy.
OBJECTIVE
To investigate the efficacy of the PolScope on imaging the spindle morphology in oocytes at the metaphase II stage before vitrification and after thawing.


METHODS
In vitro study.


METHODS
University infertility clinic and academic research laboratory.


METHODS
Oocytes at the metaphase II stage that were obtained from superovulating mice were vitrified and then thawed.


METHODS
Morphological features of the spindle in oocytes were evaluated by both the PolScope and immunofluorescent staining.


RESULTS
Using the PolScope, the morphological features of the spindle of intact thawed oocytes were undetected by 3 hours of thawing in only 25% of cases. Most of the spindle images were recognized during the first hour of observation. Additionally, the statistical analysis of agreement of spindle morphology by both the PolScope and fluorescent staining showed a weighted Kappa value of 0.70, indicating good agreement. Oocytes with good spindle morphology verified by the PolScope before vitrification had a higher survival rate of intact oocytes after thawing compared with those with poor or undetected spindle images.


CONCLUSIONS
The morphological features of the spindle in oocytes evaluated by the PolScope before freezing and after thawing are significantly correlated with those assessed by immunofluorescent staining after fixation. With the assistance of the PolScope, thawed oocytes with good spindle morphology can be verified and selected for further manipulation without fixation and staining.
Chen
Chun-Kai
CK
Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Lin-Kou Medical Center, Tao-Yuan, Taiwan.
Wang
Chia-Woei
CW
Tsai
Wan-Jin
WJ
Hsieh
Ling-Ling
LL
Wang
Hsin-Shih
HS
Soong
Yung-Kuei
YK
D000818:Animals; D002874:Chromosome Mapping; D015925:Cryopreservation; D003599:Cytoskeleton / Q000648:ultrastructure*; D005260:Female; D008540:Meiosis; D008677:Metaphase; D051379:Mice; D008813:Mice, Inbred ICR; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000166:cytology* / Q000648:ultrastructure; D014404:Tubulin / Q000032:analysis
D014404:Tubulin