[measurement] What is the directly source-reported, not estimated, colony-forming efficiency percentage, with a stated input cell number, for the Wang et al. 2025 fully chemical reprogramming protocol applied specifically to human fibroblasts?

Answer

No verified, source-quoted colony-forming efficiency percentage with a stated input cell number exists in this corpus for the 2025 fully chemical reprogramming protocol c102bfa5 applied specifically to human fibroblasts. The paper matching the task description c102bfa5, published in Nat Chem Biol (PMID 39753706, doi:10.1038/s41589-024-01799-8), reports in its abstract a "100% success rate across 15 different donors" and "efficiency...over 20-fold within 16 days", but neither figure is a colony-percentage tied to a stated input cell count, and neither is explicitly scoped to fibroblasts specifically; full text is paywalled with no PMC or open-access copy c102bfa5. A related but distinct 2025 companion paper from the same lab (Cell Stem Cell, PMID 40744016) reports chemical reprogramming yield as ">100 hCiPS colonies from a single drop of fingerstick blood" -- but this is for blood cells, not fibroblasts, and again is not expressed as a percentage of input cells ec292232. Two independent search paths -- one through the primary paper and its blood-cell companion, one through a 2025 review commentary and a Cell Stem Cell preview article discussing the same system -- both converge on the same conclusion: no accessible source states the requested figure c102bfa5``ec292232.

Summary

The research question as posed cannot currently be answered with a verified, source-quoted figure. The exact metric requested -- fibroblast-specific colony-forming efficiency percentage with a stated input cell number, for the Wang et al. 2025 fully chemical cocktail -- does not appear in any of the four sources checked across two independent submissions. What is available instead is a 100% donor success rate and a >20-fold efficiency gain within 16 days (cell type not stated as fibroblast-specific) from the primary paper's abstract, and a blood-cell-specific yield of >100 colonies per fingerstick drop from a companion paper. Neither substitutes for, nor should be read as an estimate of, the fibroblast colony percentage the question asks for.

Evidence

• Primary paper matching the 2025 chemical reprogramming protocol, Nature Chemical Biology c102bfa5 -- abstract states 100% success across 15 donors and >20-fold efficiency gain in 16 days, but not a fibroblast-specific colony percentage; full text inaccessible (paywalled, no PMC copy; platform retrieve_full_text returned mismatched, unrelated content for this PMID).
• Companion 2025 blood-cell paper, Cell Stem Cell (PMID 40744016) ec292232 -- chemical reprogramming of human blood cells, not fibroblasts; reports >100 hCiPS colonies from a single fingerstick blood drop, no percentage figure and wrong cell type for this question.
• Nature Reviews Molecular Cell Biology (2025) commentary on the same chemical reprogramming system -- searched as an independent route to the figure; abstract not indexed (OpenAlex abstract_inverted_index null), full text paywalled; nothing found. ec292232
• Cell Stem Cell preview, "Chemical reprogramming takes the fast lane" -- searched as a third independent route; paywalled (HTTP 403 on ScienceDirect); nothing found. ec292232

Methodology

Both verified submissions independently attempted to locate the specific figure via different literature paths: one traced the primary paper and its blood-cell companion paper directly; the other traced a review commentary and a preview article discussing the same chemical-reprogramming system. The two paths used non-overlapping sources and both converged on the same conclusion, so this synthesis treats the absence of the figure as corroborated by independent search rather than as a single unconfirmed gap. No numeric values required conversion or pooling, since none of the four sources checked actually states the requested metric.

Limitations

• The primary paper c102bfa5 (Nat Chem Biol) is paywalled with no PMC or open-access mirror; the requested figure may exist in the paywalled full text, methods, or supplementary materials, none of which this corpus could access.
• The accessible abstract figures (100% donor success rate; >20-fold efficiency gain) are not scoped to fibroblasts specifically and must not be used as a proxy for the requested percentage.
• Whether the platform's retrieve_full_text mismatch (returning an unrelated intracerebral-hemorrhage stem-cell review for this PMID) is a systemic indexing defect or a one-off is not established by this corpus and would need separate investigation to confirm.