NO DIFFERENCE BETWEEN COLLAGENASE TYPE I AND IV IN ISOLATION OF PORCINE TESTIS CELLS
Bibliographic record
Abstract
Testicular cell isolation is a starting step for culture, enrichment, modification or transplantation of spermatogonial stem cells. Therefore, the efficiency of enzymatic dissociation of the testis tissue is a potential limiting factor for such stem cell applications. Protocols used for testis cell isolation vary depending on the species from which the testes are collected and among laboratories, and little research has compared the virtue of different protocols. Therefore in search of an optimized protocol, we started by comparing the dissociation efficiency of collagenase type I and IV, as either type has been used in similar protocols. The testes of oneweek old piglets were surgically removed, decapsulated, trimmed, minced and exposed to collagenase (either type I or IV, 0.2% in DMEM) for 30 min to be digested, followed by an additional 20 min digestion with hyaluronidase (0.2% in DMEM). The suspension was then washed (centrifuged at 350X g for 5–7 min and the supernatant was discarded) and a combination of trypsin (0.25%) with EDTA (2.21 mM) and DNase I (0.2%) in HBSS was added for 15 min for further digestion, before fetal bovine serum (FBS) was supplied to stop the digestion. The suspension was washed again and resuspended in DMEM with 12% FBS and filtered through a 40 micrometer nylon filter. Cell populations were counted and the cell viability was determined using trypan blue exclusion. Total cell number harvested per gram testicular parenchyma were 332 ± 42 X 106 (mean ± SEM, n = 13) and 335 ± 26 X 106 (mean ± SEM, n = 14), for collagenase type I and IV, respectively, displaying no significant difference. Cell viability rates were 78 ± 2% (mean ± SEM, n = 13) and 83 ± 2% (mean ± SEM, n = 14) for collagenase type I and IV, respectively, showing no significant difference (p = 0.1). These results show that in terms of the viability and cellular yield, collagenase type I and IV are equally efficient; however, our observations of the final populations of isolated cells seemed to suggest that collagenase type IV resulted in far fewer cell clusters than collagenase type I. Further research is required to evaluate the stem cell activity of the cell populations obtained from each protocol. (poster)
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".