Variation in Human Islet Viability Based on Different Membrane Integrity Stains
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Membrane integrity fluorescent staining is used routinely to evaluate islet viability. Results are used as one of the determining factors in islet product release criteria, and are used to assess the efficacy of different culture conditions. Recently, it has been observed that there is variation in the viability staining of freshly isolated islets based on which viability assay is used. This investigation compares three membrane integrity stains for the viability assessment of isolated human islets. Fluorescein diacetate/propidium iodide (FDA/ PI), the current standard method for assessing islet viability, demonstrates intense extracellular fluorescence, reducing the differential staining of intact islets. We further evaluated SYTO-13/ethidium bromide (SYTO/ EB) and calcein AM/ethidium homodimer (C/EthD) as alternative viability assays, and found considerable variation between FDA/PI and either SYTO/EB or C/EthD staining. Preparations of human islets were obtained from cadaveric pancreata after collagenase digestion, mechanical separation, and purification by continuous Ficoll gradient centrifugation. For each preparation, two replicate samples of 50 islets were counted for each stain, and the percent viability calculated. The results for SYTO/EB and C/EthD were nearly identical [57.6 +/- 7.3% and 57.9 +/- 7.2%, respectively (mean +/- SEM), N = 11]. FDA/PI-stained islets, however, showed consistently elevated values when compared to SYTO/EB. Accurate assessment of islet viability remains a critical determinant of islet product release. The discrepancies found between FDA/PI scoring and visual quality, compared with alternative stains, suggests that the FDA/PI stain may not be the optimal approach to assess islet viability.
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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 | 0.000 | 0.000 |
| 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 it