GB/T 41021-2021
Forensic sciences—Content and format of DNA identification report (English Version)

Standard No.

GB/T 41021-2021

Language

Chinese, Available in English version

Release Date

2021

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 41021-2021

Introduction

Analysis of the core framework of the standard

Type of document	Essential elements	Key differences
Appraisal certificate	Cover page + statement + text (including argumentation) + attachments	Must include argumentation chapter and clear appraisal opinion
Test report	Cover page + statement + text + attachments	Only objective record of test results

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Detailed explanation of key technical requirements

1. Specifications for genetic marker testing

The standard clarifies the technical requirements for three types of DNA polymorphism testing:

• Autosomal STR: The typing expression needs to be tested by ABI Genetic Analyzer and other equipment. Homozygotes are marked with single numbers, and mixed typing requires the peak height ratio.
• Y-STR: The possibility of paternal mutation should be noted, and exclusion conclusions should be cautious.
• Mitochondrial DNA: The comparison region is required to be >100bp, and the signal intensity of heterogeneous polymorphic points needs to be marked.

2. Rules for Expression of Identification Opinions

Typical Case: When mixed STR typing is detected, if it meets the mixed characteristics of two individuals:
"Mixed genotypes were detected in sample No. 3, including DNA typing of Zhang (sample 1) or Li (sample 2), with a likelihood rate of 1.2×10⁸"

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Key points for the implementation of the standard

1. Document production specifications

Items	Requirements
Text color	Black (Images can be in color)
Seal specifications	A red appraisal seal shall be stamped on the first page number and the last page date
Archive requirements	Inspection maps, original data and approval records must be kept for 20 years

2. Handling of special circumstances

An inspection report should be issued instead of an appraisal certificate in the following circumstances:

• Only field samples without matched samples
• DNA results from different samples are contradictory
• Mixed typing cannot identify individual sources

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Analysis of standard evolution

This standard systematically integrates the three major technical systems of DNA identification documents (autosomal STR/Y-STR/mtDNA) for the first time. Compared with the GA/T383 series of standards:

1. Added mitochondrial DNA heteroplasmy annotation specifications
2. Refine the expression threshold of mixed typing (peak height ratio ≥60%)
3. Clarify the encryption requirements for electronic data archiving

GB/T 41021-2021 Referenced Document

• GB/T 9704 Layout key for official document of Party and government organs

GB/T 41021-2021 history

• 2021 GB/T 41021-2021 Forensic sciences—Content and format of DNA identification report

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