Evidence map›Paper›PMID 40775199›Full record

ArticleForensic science, medicine, and pathology2026

Forensic analysis of formalin-fixed non-paraffin-embedded tissues: a comparative study of STR and mtDNA profiling.

Kangana Aggarwal, Nidhi Sharma, Braja Kishore Mohapatra, Kamal Chauhan, Harpreet Singh, Chittaranjan Behera

Abstract readComparative Study
PubMed Publisher
In one paragraph

Article in Forensic science, medicine, and pathology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Kangana AggarwalDepartment of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, Room No.303, Second Floor, New Delhi, New Delhi, 110029, India.
Nidhi SharmaDepartment of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, Room No.303, Second Floor, New Delhi, New Delhi, 110029, India.
Braja Kishore MohapatraPrincipal Scientific Officer and Head of Department, Central Forensic Science Laboratory, DFSS, New Delhi, 110003, India.
Kamal ChauhanPrincipal Scientific Officer and Head of Department, Central Forensic Science Laboratory, DFSS, New Delhi, 110003, India.
Harpreet SinghBMI Centre, Indian Council of Medical Research (ICMR), New Delhi, 110029, India.
Chittaranjan BeheraDepartment of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, Room No.303, Second Floor, New Delhi, New Delhi, 110029, India. drchitta75@rediffmail.com.

Funding

Indian Council of Medical Research Indian Council of Medical Research
6 · The paper itself

Abstract

Formalin fixation is a common practice for preserving forensic samples in developing countries like India, but it can adversely affect DNA quality and hinder downstream molecular analyses. This study investigated the effectiveness of mitochondrial DNA (mtDNA) typing in formalin-fixed, non-paraffin-embedded tissues when conventional Short Tandem Repeat (STR) profiling fails due to DNA degradation. Tissue samples from 30 deceased individuals were fixed in 10% unbuffered formalin and divided into four groups based on fixation duration (1-4 weeks). DNA was extracted, quantified, and subjected to STR profiling. Samples with incomplete STR profiles underwent mtDNA sequencing targeting the hypervariable regions to assess maternal lineage and haplogroup distribution. DNA quantification revealed significant degradation across all groups, with decreasing DNA concentrations over time. STR profiling showed limited success, with only 13 out of 27 loci amplified in group 1 and 7 loci in group 2, while groups 3 and 4 yielded no STR profiles. In contrast, mtDNA typing was successful in all samples, revealing distinct haplogroups and haplotypes. Haplogroup M was the most prevalent (50%), with 12 distinct subhaplogroups identified. The presence of East Asian (A11, G1b) and West Eurasian (H10g, T2H2, HV2a, U, R) haplogroups reflects historical migrations and admixture in the Indian population. The study highlights the limitations of STR profiling in formalin-fixed tissues and demonstrate the robustness of mtDNA typing. Incorporating mtDNA analysis into forensic protocols can enhance the reliability and comprehensiveness of DNA profiling results, particularly when dealing with challenging samples. Further research is needed to refine tissue preservation methods and optimize DNA recovery from formalin-fixed tissues to advance molecular analyses in forensic and retrospective studies.

Indexed as

DNA FingerprintingDNA, MitochondrialFixativesFormaldehydeMicrosatellite RepeatsTissue FixationDNA Degradation, NecroticFemaleHaplotypesHumansIndiaMaleMiddle AgedPolymerase Chain ReactionSequence Analysis, DNADNA, MitochondrialFixativesFormaldehydeDegraded DNADNA profilingForensic samplesFormalin-fixed tissuesMitochondrial DNA sequencingShort tandem repeats (STR)

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.