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Updated: Mar 23, 2026
Morphometric Protocol for the Objective Assessment of Blastocyst Behavior During Vitrification and Warming Steps
Published on: February 28, 2019
Comparison of mechanical artificial shrinkage methods in mouse blastocyst vitrification
Purpose Of Investigation:
This study was designed to determine which mechanical artificial shrinkage (AS) method, conducted by puncture, pipetting, or aspiration, was effective in increasing the re-expansion rate of mouse blastocysts.
Materials And Methods:
In each group, 30 mouse blastocysts were used. Before vitrification, the blastocoelic cavity was collapsed by puncture with a micro-needle, pipetting with a micro-glass pipette, and direct aspiration with an ICSI pipette. After thawing, the re-expansion rate of blastocysts was examined for each AS method. Re-expansion rate was checked at three, five, and seven hours after thawing.
Results:
The number of re-expanded mouse blastocysts at five hours after thawing was 12 in the puncture with a micro-needle group, 11 in the pipetting with a micro-glass pipette group, and 24 in the direct aspiration with an ICSI pipette group. The cumulative number of re-expanded mouse blastocysts at seven hours after thawing was 20 in the puncture with a micro-needle group, 20 in the pipetting with a micro-glass pipette group, and 28 in the direct aspiration with an ICSI pipette group. There were statistically significant differences in the cumulative number of re-expanded mouse blastocysts between five and seven hours after thawing (p = 0.001 and 0.021, respectively).
Conclusions:
Direct aspiration with an ICSI pipette resulted in a higher re-expansion rate than the puncture and pipetting methods. It can be considered that the direct aspiration method is more convenient and simpler than the other two methods.
Insights
Direct aspiration using an ICSI pipette is the most effective method for increasing mouse blastocyst re-expansion rates after vitrification. This technique offers a simpler and more convenient approach compared to puncture or pipetting methods.
Area of Science:
- * Reproductive biology
- * Cryobiology
- * Developmental biology
Background:
- * Blastocyst cryopreservation is crucial for assisted reproductive technologies.
- * Successful cryopreservation requires efficient methods for blastocyst shrinkage before vitrification.
- * Various mechanical artificial shrinkage (AS) methods exist, but their comparative efficacy is not well-established.
Purpose of the Study:
- * To compare the effectiveness of three mechanical artificial shrinkage (AS) methods: puncture, pipetting, and direct aspiration.
- * To determine which AS method yields the highest re-expansion rate in mouse blastocysts after thawing.
- * To evaluate the convenience and simplicity of each AS method.
Main Methods:
- * 30 mouse blastocysts were allocated to each of three AS groups: puncture with a micro-needle, pipetting with a micro-glass pipette, and direct aspiration with an ICSI pipette.
- * Blastocoelic cavity collapse was performed before vitrification.
- * Re-expansion rates were assessed at 3, 5, and 7 hours post-thawing.
Main Results:
- * At 5 hours post-thaw, direct aspiration yielded 24 re-expanded blastocysts, compared to 12 (puncture) and 11 (pipetting).
- * At 7 hours post-thaw, cumulative re-expansion was 28 for direct aspiration, versus 20 for both puncture and pipetting.
- * Statistically significant differences in cumulative re-expansion were observed at 5 and 7 hours (p = 0.001 and 0.021).
Conclusions:
- * Direct aspiration using an ICSI pipette significantly enhances mouse blastocyst re-expansion rates post-thaw.
- * The direct aspiration method is more effective and simpler than puncture or pipetting for AS.
- * This technique holds promise for improving blastocyst cryopreservation outcomes.
