Ninhydrin
chemical compound
Ninhydrin (2,2-dihydroxyindane-1,3-dione) is an organic compound with the formula C6H4(CO)2C(OH)2. It is used to detect ammonia and amines. Upon reaction with these amines, ninhydrin gets converted into deep blue or purple derivatives, which are called Ruhemann's purple. Ninhydrin is most commonly used to detect fingerprints in forensic cases, as the terminal amines of lysine residues in peptides and proteins sloughed off in fingerprints react with ninhydrin.
Ninhydrin is a white solid that is soluble in ethanol and acetone. Ninhydrin can be considered as the hydrate of indane-1,2,3-trione.
History
Ninhydrin was discovered in 1910 by the German-English chemist Siegfried Ruhemann (1859–1943). In the same year, Ruhemann observed ninhydrin's reaction with amino acids. In 1954, Swedish investigators Oden and von Hofsten proposed that ninhydrin could be used to develop latent fingerprints.
Uses
Ninhydrin can be used in Kaiser test to monitor deprotection in solid phase peptide synthesis.
“Ninhydrin” enters the record as chemical compound. Crown Archives preserves that source wording while asking what Ninhydrin, chemical and compound can confirm, complicate or overturn.
Why this record matters
“Ninhydrin” is worth following because a concise public description often conceals a longer documentary argument. Here, Ninhydrin, chemical and compound provides the most credible route into that argument.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Jul 19, 2026. The linked authority identifier is Q421098. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1910, 1859, 1943 and 1954.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Ninhydrin”, its source revision and the description used here.
- Expand the search: follow Ninhydrin primary sources, Ninhydrin archive and Ninhydrin research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Ninhydrin”?
- Has classification or technical consensus changed since the cited source?
- Which observation, specimen, dataset or publication supports the account?
Search terms from this dossier
This entry incorporates text from “Ninhydrin” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.