Archived medical specimens disaster victim identification may offer a powerful source of antemortem DNA
DNA, or Deoxyribonucleic Acid, is the genetic material found in cells, composed of a double helix structure. It serves as the genetic blueprint for all living organisms. Read Full Definition for disaster victim identification. A study published on 30 September 2026 examined whether samples kept could aid identification when references were unavailable.
- Why disaster victim identification needs antemortem references
- What the 2026 study examined
- Why an archived clinical specimen can be stronger than a personal item
- Which archived specimens are most challenging?
- The laboratory controls that matter
- DNA comparison is not the final identification decision
- Legal, ethical and privacy questions
- What this means for DVI preparedness
- What the study does—and does not—establish
- Source and further reading
The findings are important, but they require careful interpretation. An archived biopsy or diagnostic swab may contain DNA originating directly from the missing person. It does not, by itself, complete an identification. Specimen identity, chain of custodyChain of custody - The process used to maintain and document the chronological history of the evidence. Documents record the individual who collects the evidence and each person or agency that subsequently takes custody of Read Full Definition, analytical quality, legal authority and reconciliation with postmortem and other evidence
Evidence is any form of proof, such as objects, materials, or scientific findings, presented to establish or disprove a fact in a legal proceeding. It is used to reconstruct events and link or exclude individuals Read Full Definition remain essential.
Key point
The value of an archived clinical specimen is not merely that it contains DNA. Its principal advantage is that—when correctly labelled and linked to the medical record—it can function as a direct antemortem reference from the missing person rather than an indirect reference from a relative or personal object.
Why disaster victim identification needs antemortem references
In a DNA-led disaster victim identification (DVI) operation, generating a DNA profile from human remains is only one side of the comparison. Investigators also need reliable antemortem information against which the postmortem profile can be evaluated.
Common DNA reference sources include:
- Direct personal references, such as a toothbrush, razor or stored biological specimen believed to have been used only by the missing person.
- Family-reference samples collected from biological relatives and interpreted using a documented pedigree and kinship statistics.
- Previously generated DNA profiles, where identity, quality and authority for comparison can be established.
Each approach has limitations.
A toothbrush may contain DNA from more than one household member.
A personal item may have been mislabeled or shared.
Family comparisons are less informative when only distant relatives are available.
This can be complicated by incomplete pedigrees or archived medical specimens disaster victim identification and undisclosed biological relationships.
The loss of several family members also affects conclusions.
These difficulties become particularly severe when entire households are affected by the same disaster. In that situation, archived hospital material may preserve a direct biological reference even when the missing person’s home, personal effects and closest relatives are no longer available.
What the 2026 study examined
The new International Journal of Legal Medicine study followed the identification challenges created by the 7 October 2023 attack in Israel. Investigators used Ministry of Health repositories to develop what the authors describe as a “self-direct-reference” antemortem DNA database.
The researchers evaluated 151 archived clinical specimens collected between 2003 and 2023.
Additionally, these specimens support archived medical specimens disaster victim identification research.
- 131 histological specimens, including formalin-fixed paraffin-embedded tissue blocks and cytology slides;
- 8 diagnostic swabs; and
- 12 blood or serum specimens.
They assessed four major variables: specimen source, extraction method, incubation protocol, and specimen age.
DNA was amplified with the Investigator 24plex system.
Performance was measured by the number of informative autosomal STR loci recovered.
There were 21 loci available for assessment.
This informs archived medical specimens disaster victim identification.
Depending on the specimen type and processing method, the reported mean locus
A locus is the precise position of a gene on a chromosome. Different alleles of the same gene occupy the same locus. Read Full Definition recovery ranged from approximately 67% to 100%.
Important interpretation
A 67–100% mean locus-recovery range is not the same as saying that every specimen produced a complete, identification-ready profile. It describes the proportion of informative loci recovered under particular specimen and processing conditions. Case-level usefulness still depends on profile completeness, artefacts, contaminationContamination - The unwanted transfer of material from another source to a piece of physical evidence. The inadvertent touching of a weapon, thereby adding fingerprints to it is an example of evidence contamination. Read Full Definition risk, comparison strategy and the strength of the resulting match.
Why an archived clinical specimen can be stronger than a personal item
A properly documented pathology block or diagnostic specimen was collected from a known patient during healthcare. If the specimen identifier, patient identity and repository record remain reliable, the biological material should originate from that patient.
This can offer an evidential advantage over an object collected from a residence. A toothbrush labeled with a person’s name may have been shared, moved or contaminated. A hospital specimen is not automatically immune to error, but it begins with a formal accessioningIn the forensic context, accessioning refers to the specialized process of receiving, handling, and documenting evidence and samples collected at crime scenes or related to criminal investigations. This process is crucial for maintaining the integrity Read Full Definition process and a clinical record that can be independently checked.
The comparison can also be more straightforward. A sufficiently complete direct reference can be compared with the postmortem profile as a same-person proposition. A family sample instead requires a relationship hypothesis, an accurate pedigree, population data
Information in analog or digital form that can be transmitted or processed. Read Full Definition and a kinship calculation whose strength depends on the available relatives.
Which archived specimens are most challenging?
Formalin-fixed paraffin-embedded tissue
FFPE tissue is widely retained in pathology archives, but formalin can cross-link DNA to proteins and fragment the moleculeA molecule is a fundamental unit of matter composed of two or more atoms that are chemically bonded together. It is the smallest possible amount of a particular substance that retains all of the unique Read Full Definition. Paraffin removal, tissue digestion and DNA purification therefore require procedures designed for damaged material. Longer storage, fixation conditions, tissue type and block handling can all affect recovery.
Short forensic STR amplicons may still be recovered, but laboratories must anticipate preferential loss of larger targets, allelic dropout and incomplete profiles. Replicate analysis or an alternative marker system may be justified when the comparison is critical and sufficient material remains.
Cytology slides
Cytology preparations can contain limited cellular material. The cells may also have been stained, mounted or exposed to chemicals that affect extraction and amplification. Sampling must preserve as much diagnostic material as possible while avoiding transfer between slides.
Diagnostic swabs and stored blood
These may provide higher-quality DNA, but performance depends on the collection device, storage temperature, preservatives, specimen age and the volume remaining. Serum generally contains less cellular DNA than whole blood and should not be assumed to behave identically.
The laboratory controls that matter
Using an old clinical sample for identification should be treated as a controlled forensic process, not as an informal transfer from a hospital to a DNA laboratory. A defensible workflow should address:
- Identity verification: confirmation that the medical-record identity and specimen accession number refer to the correct patient.
- Documented transfer: tamper-evident packaging, transfer records and continuous chain of custody.
- Contamination assessment: reagent blanks, appropriate positive and negative controls, staff elimination procedures and review of previous handling.
- Sample conservation: justification of how much material is consumed and whether clinically important material must remain available.
- Method suitability: validated extraction and profiling procedures for the relevant specimen type and degree of degradation.
- Replicate or confirmatory analysis: especially for partial profiles, unexpected mixtures or low-template findings.
- Independent review: technical and administrative review before the profile enters the comparison and reconciliation process.
DNA comparison is not the final identification decision
International DVI practice separates the collection and analysis of antemortem information, the examination of human remains and the final reconciliation process. DNA is one primary identification method, alongside methods such as fingerprintsFingerprint, impression made by the papillary ridges on the ends of the fingers and thumbs. Fingerprints afford an infallible means of personal identification, because the ridge arrangement on every finger of every human being is Read Full Definition and dental comparison, but the result must remain connected to the correctly numbered remains.
This distinction is crucial in fragmented or commingled cases. A scientifically correct DNA profile can still contribute to a wrong identification if a bone, tooth, tissue sample or temporary mortuary number was assigned incorrectly. Duplicate sampling can also make one person appear to represent several unidentified sets of remains.
Accordingly, a strong DNA association should be reconciled with:
- recovery location and remains numbering;
- anthropological assessment and commingling review;
- dental, fingerprint and medical evidence where available;
- the missing-person list and verified demographic information;
- duplicate-profile searches; and
- documented authority for the final identification decision.
Legal, ethical and privacy questions
Material retained for diagnosis was not necessarily collected with disaster identification in mind. Its later forensic use therefore raises questions beyond analytical performance.
Authorities need a clear legal basis for access and transfer. Health-information confidentiality, consent rules, retention law and judicial or emergency powers differ between jurisdictions. Governance should also define who may search the resulting profiles, how long data are retained and whether the information may be repurposed for criminal investigation, research or database searching.
The principle of data minimization is particularly important. A DVI program usually needs identity-relevant genetic information—not unrestricted access to medical records or genome-wide health information. STR profiling and record handling should be limited to the legitimate identification purpose, with access logs and defined deletion or return procedures.
Related Simply Forensic guides
What this means for DVI preparedness
The study suggests that medical repositories should be considered during preparedness planning rather than only after conventional references fail. That does not mean every hospital specimen should be preemptively profiled. It means DVI plans should establish, before a disaster:
- which repositories retain potentially useful specimens;
- who has authority to request and release them;
- how identity and accession records will be verified;
- which laboratories can process FFPE and other archived material;
- how limited clinical material will be conserved;
- how profiles will be exchanged securely; and
- how results will enter the formal reconciliation process.
Cross-border disasters make this planning even more important. The remains, relatives, medical records and pathology specimens may be held in different jurisdictions, each with its own privacy, evidentiary and data-transfer requirements.
What the study does—and does not—establish
The research demonstrates that archived clinical specimens can remain useful sources of autosomal STR information after many years and provides practical evidence that specimen type and processing method affect recovery.
It does not establish that every archived specimen will yield a complete profile, that a hospital label can never be wrong, or that a DNA match alone completes the identification. Nor does analytical success resolve consent, privacy, ownership or proportionality questions.
The responsible conclusion is narrower and more useful: when ordinary references are unavailable, a correctly documented archived clinical specimen can provide a direct antemortem DNA reference—but it must enter a validated, legally authorized and multidisciplinary DVI system.
Source and further reading
- Ido A, Avrahami K, Feinberg T, et al. Archived medical specimens as antemortem DNA references for disaster victim identification: optimization study following the October 7 massacre. International Journal of Legal Medicine. Published 30 September 2026.
- INTERPOL: Disaster Victim Identification.
This article discusses the scientific and operational implications of newly published research. Local law, ethics requirements and accredited laboratory procedures govern the use of clinical specimens in actual identification operations.
