Colony Forming Cell Assays for Human Hematopoietic Progenitor Cells
Bibliographic record
Abstract
Hematopoietic stem cells (HSCs) present in small numbers in adult bone marrow (BM), peripheral blood (PB) and umbilical cord blood (CB) produce a heterogeneous pool of progenitors that can be detected in vitro using colony forming cell (CFC) assays. Hematopoietic progenitor cells proliferate and differentiate to produce colonies of maturing cells when cultured in a semisolid methylcellulose-based medium that is supplemented with suitable growth factors and other supplements. The colonies are then classified and enumerated in situ by light microscopy or an automated imaging instrument. CFC assays are important tools in basic hematology research but are also used by clinical cell processing laboratories to measure the progenitor cell content of BM, CB and mobilized PB (MPB) preparations used for cell transplantation. Standard CFC assays for human progenitor cells require a culture period of at least 14 days to enable optimal outgrowth and differentiation of the maximum number of CFCs in a cell preparation. In this chapter protocols are described for the detection and enumeration of myeloid multipotential progenitors and committed progenitors of the erythroid, monocyte, and granulocyte lineages in samples from human PB, MPB, BM, and CB. In addition protocols are described for a modified version of the CFC-assay that allows accurate enumeration of total CFC numbers in CB or MPB after a culture period of only 7 days, but without distinction of colony types.
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How this classification was reachedexpand
Direct model labels (unvalidated)
Per-model category and study-design labels from the labeling rounds. They are machine output, unvalidated, and the disagreement between models ships as data. No study design here is MEDLINE-validated yet.
| Model arm | Categories | Study design | Confidence |
|---|---|---|---|
| gemma | no category Domain: not available · Genre: Methods About the Canadian research system: no · About a Canadian topic: no | Bench or experimental | low |
| gpt | no category Domain: not available · Genre: Methods About the Canadian research system: no · About a Canadian topic: no | Bench or experimental | high |
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 | 0.000 |
| 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 itClassification
machine, unvalidatedLabeled directly by 2 models reading the full record.
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".