Effect of Slow Freezing Versus Vitrification on the Recovery of Mouse Embryonic Stem Cells
Bibliographic record
Abstract
The purpose of this study was to cryopreserve mouse embryonic stem (ES) cells R1 line and determine cell viability, morphology, the number of colonies, and the Alkaline Phosphatase (AP) activity. In addition, the expression of transcription factors such as the stage-specific antigen (SSEA-1) and Octamer-4 (Oct-4) were evaluated before and after cryopreservation. The effects of two methods of cryopreservation, slow freezing and vitrification, were studied. The ES cells were cryopreserved either as single cells or as clumps. The viability of a single cell after slow freezing was 88%, but after vitrification no single cell was recovered. Surviving clumps after slow freezing quickly recovered and exhibited a morphology indistinguishable from noncryopreserved cells. After vitrification, 2 weeks of culture were required for the cells in clumps to proliferate enough for subculturing. Analysis of cloning efficiency and the colonies morphology were based on a mouse colony rating scale and their characteristic. The colonies from the slow-freezing group were compared to colonies from the control group, which were the cells before cryopreservation, and they showed the same cloning efficiency and morphology. The colonies from the vitrified group were compared to the colonies from the control group, and they showed differences in cloning efficiency on the mouse colony rating scale A (<0.05) and C (<0.05) but they did not show differences in their morphology. The biggest clumps from both experimental groups showed a reduction of viability in the center area compared to the fresh ones. The survival rate of the clumps in the slow-freezing and rapid-thawing group was 75% and in the vitrified group 25%. The colonies from the control group and both experimental cryopreservation groups show the same activity of AP, and they were all positive for SSEA-1 and Oct-4. The conventional slow-freezing method of cryopreservation of single cells and clumps is reliable and effective for the cryopreservation of mouse R1 ES cells. Vitrification can be used for cryopreservation of these same cell clumps but with lower recovery using the conditions that we used.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".