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ICS13.310
People's Republic of China Public Security Industry Standard GA/T382-2002
Criterion for the forensic DNA laboratory2002-04-24 Issued
The Ministry of Public Security of the People's Republic of China Issued
2002-07-01 Implementation
GA/T 382-2002
This standard is proposed and managed by the National Criminal Technology Standardization Technical Committee (CSBTS/TC179). The main drafting unit of this standard: the Physical Evidence Identification Center of the Ministry of Public Security. The participating drafting units of this standard: Shanghai Public Security Bureau, Liaoning Provincial Public Security Department, Beijing Municipal Public Security Bureau, Guangzhou Municipal Public Security Bureau, Heilongjiang Provincial Public Security Department.
Drafters of this standard: Ye Jian, Chen Song, Zhou Huaigu, Liu Bing. 1 Scope
People's Republic of China Public Security Industry Standard Criterion for the forensic DNA laboratory
Criterion for the forensic DNA laboratory This standard specifies the basic requirements that forensic DNA laboratories should comply with. This standard applies to DNA laboratories engaged in forensic science testing. 2 Definitions
This standard adopts the following definitions.
2.1 Technical manager
A person who manages the technical operations of the laboratory.
2.2 Examiner or analyst
A person who conducts case testing, analyzes test results, and drafts identification documents. 2.3 Technician
A person who performs actual testing operations under the guidance of the examiner. 2.4 Commercial test kit Commercial test kit A kit specifically used for DNA identification provided to inspectors. 2.5 Laboratory
A place where forensic DNA testing is carried out.
2.6 Polymerase chain reaction Polymerase chain reaction-PCR An enzymatic amplification process of a specific DNA fragment. 2.7 Proficiency testing GA/T382—2002
A quality assurance measure used to monitor testing practices and identify areas for improvement. Proficiency testing can be as follows: (1) Internal testing: prepared and managed by the laboratory itself. (2) External testing: should be conducted by other organizations. 2.8 Restriction fragment length polymorphism restriction fragment length polymorphism-RFLP Due to the different restriction endonuclease sites and/or the different numbers of repeated sequences in each fragment, different lengths of DNA fragments are obtained after digestion with specific enzymes.
2.9 Amplification blank control amplification blank control includes all amplification reagents except the DNA template and is used to test whether the amplification reagents are contaminated by DNA. 2.10 Critical reagents critical reagents Reagents that have been tested with known samples before testing to prevent unnecessary loss of physical evidence. 2.11 Forensic DNA testing forensic DNA testing The identification of biological evidence in criminal evidence using DNA technology. 2 Known samples knownsamples
Approved by the Ministry of Public Security of the People's Republic of China on April 24, 2002, implemented on July 1, 2002
Biological materials with known characteristics and typing.
2.13 Audit
GA/T382-2002
Evaluation, determination or verification of quality-related behaviors. 2.14 Technical validation
The process used to determine the effectiveness and reliability of the methods used in forensic case analysis, which includes: a) Initial technical validation is the identification of new forensic DNA technology, which includes the recognition of experimental data and the confirmation of the scope of application of the technology.
b) Internal technical evaluation is the accumulation of test data within the laboratory to prove whether the established methods and procedures are consistent with the expected results.
2.15 Analytical procedure analytical procedure has clear steps to ensure consistent operation and reduce analytical errors. 2.16 Quality manual qualitymanual
A document that states the quality policy, quality system and quality practices of an organization. 2.17 Quality assurance qualityassurance includes necessary systematic actions to prove that products or services meet specific quality requirements. 3 Personnel
3.1 Position setting
Forensic science DNA laboratories should set up three types of responsible positions, namely technical supervisors, inspectors, and technicians. 3.2 Personnel quality requirements
3.2.1 Technical supervisors: They should have a bachelor's degree or above or professional and technical qualifications of deputy chief forensic physicians or above, majoring in biology, forensic medicine and related disciplines, more than five years of experience in forensic science DNA case detection, and understand the progress of DNA typing. 3.2.2 Inspectors: They should have a bachelor's degree or above, professional and technical qualifications and identification qualifications, majoring in biology, forensic medicine and related disciplines, more than three months of experience in receiving DNA testing technology training in provincial and ministerial DNA laboratories, more than one year of work experience in forensic science DNA laboratories, and pass simulated case inspections and qualification tests. 3.2.3 Technician: Should have a college degree or above, and have received on-the-job training for inspectors for more than half a year. 3.3 Job Responsibilities
3.3.1 Technical Supervisor: Manage the technical operation of the laboratory, solve technical problems arising in the inspection; organize the inspection and re-inspection of major cases and difficult cases; be responsible for the technical training and assessment of inspectors and technicians; issue appraisal documents and propose new technical directions. 3.3.2 Inspector: Mainly conduct case inspection, analysis of inspection results, drafting of appraisal documents, and assist the technical supervisor to complete other laboratory work.
3.3.3 Technician: Assist the inspector in case inspection, prepare daily reagents and prepare supplies for the experiment. Technicians cannot participate in the analysis of inspection results, the drafting of appraisal documents, or testify in court. 4 Instruments and Reagents
4.1 Instruments Only
4.1.1 The laboratory should be equipped with instruments and equipment necessary for the experimental methods it applies. 4.1.2 Instruments and equipment should be regularly inspected and calibrated. 4.1.3 Newly purchased instruments and equipment, or existing instruments and equipment after maintenance, should be calibrated before use. 4.2 Materials and reagents
4.2.1 The laboratory should be equipped with the materials and reagents necessary for the experimental methods it applies. 4.2.2 Commercial kits should indicate the arrival date and expiration date, and the reagents prepared in the laboratory should indicate the name, concentration, preparation time, storage conditions, expiration date, etc. on the container.
GA/T382~-2002
4.2.3 The laboratory should determine the key reagents and evaluate them before use. Key reagents include: restriction endonucleases, gene analysis kits, agarose gels for RFLP analysis, membranes for transfer blotting, K526DNA or other human DNA controls, molecular weight standards for RFLP analysis, and TaqDNA polymerase. 5 Laboratory settings
5.1 Basic area settings
5.1.1 The DNA laboratory must have three areas for extraction, PCR reaction, and detection. 5.1.2 Extraction room: mainly used for DNA extraction and DNA quantification. For samples with extremely low DNA content, such as hair shafts, old bones, etc., a special area should be set up for DNA extraction. 5.1.3 PCR reaction room: mainly used for sample addition and amplification of PCR reactions. 5.1.4 Detection room: mainly used for detection of amplified products. 5.2 Other area settings
5.2.1 Initial inspection room: mainly used for case registration and inquiry, initial inspection of samples, and photographic and video fixation. 5.2.2 Preparation room: mainly used for reagent preparation, disinfection of consumables, etc. 5.2.3 Result analysis room: mainly used for analysis of test results, file checking and comparison, etc. 6 Materials
6.1 Operation manual
6.1.1 Experimental methods: various DNA extraction methods, DNA quantification methods, DNA typing methods and procedures. 6.1.2 Instrument operation: operation and use methods of various instruments. 6.1.3 Reagent preparation: preparation methods, storage methods and dosages of various reagents. 6.2 Instructions
6.2.1 Commercial reagent kits.
6.2.2 Main instruments and equipment.
6.3 Case records
6.3.1 Case registration: including case acceptance records, specimen storage or return records, inspection handover records, identification document issuance records, etc. 6.3.2 Inspection records: including DNA extraction records, PCR reaction records, electrophoresis detection records, etc. 6.3.3 Identification documents: including identification books or inspection reports, inspection result maps, data analysis, etc. 6.4 Frequency survey data and calculation methods
Including the number, source and nationality of frequency surveys, various probability calculation methods, etc. 6.5bzxZ.net
Qualification test records, personal training records. 6.6 Method approval records.
6.7 Quality control rules and verification records.
6.8 Safety rules.
6.9 Other information
Warranty records of major instruments and equipment, lists of stored reagents, methods for preparing reagents, etc. 7 Method approval
7.1 DNA analysis method approval
7.1.1 Use DNA analysis methods verified and approved by the DNA Expert Committee. 7.1.2 Select standard samples: use fresh tissue or body fluid spots. 7.1.3
3Consistency: The test results of the same sample are consistent within the laboratory or between different laboratories. 7.1.4 Population survey: Investigate the allele distribution data and family analysis results between different races. 3
GA/T382-—2002
7.1.5 Identity test: The typing results of various tissues and stains of the same individual should be consistent. 7.1.6 Mixed sample typing: Mix known samples and use this method to test whether the DNA types of each known sample can be distinguished. 7.1.7 Environmental tolerance test: Treat known samples in different environments (temperature, humidity, ultraviolet rays, etc.) and use this method to type, and observe whether the results are contradictory.
7.1.8 Matrix test: Mix body fluids with common substances (such as fuel, soil) and test them or apply them on common carriers (fabrics, fur, etc.) for testing, and observe whether the results are consistent.
7.1.9 Species-specific test: verify whether the method can type DNA from biological samples other than humans. 7.1.10 Sensitivity test: determine the minimum sample size required for reliable typing. 7.2 Approval of loci
7.2.1 The loci used in DNA typing should be genetically stable, and the loci used for paternity identification should have a low probability of mutation/recombination. 7.2.2 The loci should be accurately located in the chromosome. The restriction endonucleases and probes used for RFLP loci should be accurately described; for PCR loci, the primers should be accurately described (if probes are required, they should also be described). 7.2.3 Allele naming: Alleles should be named numerically according to the number of repeats or characteristic sequences. 7.3 Approval of RFLP method
7.3.1 Restriction endonucleases: Enzyme digestion conditions should be strictly controlled and known controls should be set to ensure sufficient enzyme digestion at the restriction site. 7.3.2 Separation: Electrophoresis conditions should be strictly specified. 7.3.3 Transfer: Transfer conditions should be strictly specified. 7.3.4 Detection: Hybridization and elution conditions should be strict to ensure specificity of results. 7.3.5 An accurate fragment size determination procedure must be determined. 7.4 Approval of PCR and related test methods
7.4.1 Amplification
7.4.1.1 PCR primer sequences must be indicated (except for commercial kits). 7.4.1.2 Amplified samples must be strictly protected from contamination by amplified products. 7.4.1.3 Amplification reaction conditions and reagent (primers, enzymes, ions) concentrations should be strictly controlled to ensure consistency of results. 7.4.2 PCR product detection
7.4.2.1 Positive and negative controls are required for sample amplification analysis. 7.4.2.2 Typing without hybridization
a) If PCR products are directly typed, appropriate molecular weight standards should be used to identify alleles. b) If PCR products are subjected to other tests, appropriate internal standards must be used. c) For fragment length polymorphism analysis, an allele ladder should be used. 7.4.2.3 Typing by hybridization
a) Hybridization and elution conditions must be strictly unified to ensure the specificity of the results. b) If the DNA is directly fixed to the membrane, a positive control must be used to test whether it is connected. c) If the probe is directly fixed to the membrane, a certain method must be used to determine whether the sample to be tested contains amplification products. 7.4.3 DNA sequence determination
8 Analytical procedure requirements
8.1 Preliminary sample inspection
Carry out a preliminary inspection to determine whether the basic conditions for DNA testing are met. Before the inspection, design how to use the smallest sample to obtain the maximum amount of information. Cases and related samples that do not meet the inspection conditions can only be returned with the consent of the technical supervisor. Once the samples enter the laboratory, they must be strictly managed, labeled, and the sample handling form must be filled in. When transferring or adding samples, they must be signed and checked by others. 8.2 DNA extraction
The method of DNA extraction should be determined according to the designed inspection plan, and cross-contamination of samples should be strictly prevented. Electrophoresis, UV absorption, fluorescence, hybridization and other methods should be used to evaluate the purity, quality and human DNA content of DNA. 8.3 RFLP analysis 8.3.1 Restriction enzyme digestion: Before using a restriction enzyme, a preliminary experiment should be conducted to test its enzyme activity and the size of the fragments produced after digestion of human genomic DNA. 8.3.2 Gel electrophoresis: Visible or fluorescent markers should be used to observe the swimming speed; molecular weight markers should be used to determine the size of sample fragments; known human sample controls should be used to observe whether the typing is accurate and whether the system is efficient and correct. 8.3.3 Transfer/hybridization: Human positive control samples and molecular weight standards should be used to test the transfer efficiency, hybridization and elution conditions. 8.3.4 Autoradiography and image analysis: Continuously press X-ray films to obtain the best resolution effect; use molecular weight standards to calculate the sample band size. 8.3.5 Known human DNA controls.
8.4PCR analysis
8.4.1 Strictly set positive (human DNA samples of known type) and negative (no DNA blank) controls. 8.4.2 If necessary, set blank controls in the area near the on-site test materials. 8.4.3 During the test, the sample should be electrophoresed on the lanes between the allele mixture or the molecular weight standard. 9Qualification test
9.1Public test
9.1.1 The laboratory should participate in a public test every two years. DNA testers should participate in two public tests every year, one of which should be provided by an external party.
9.1.2 The samples for public tests should be blood spots or other body fluid spots, which can be single samples or mixed samples, and negative controls should be set at the same time. The carrier of the sample should be clean cotton (gauze) cloth, cotton swab or other suitable carrier. The DNA type of the sample will not be notified to the testee in advance. The organizer should retain some samples to be tested for verification. The test results are released by the organizer. 9.2 Blind test
9.2.1 Blind test is organized and implemented by relevant departments without the knowledge of DNA laboratory, and is carried out in the form of routine inspection cases. 9.2.2 Blind test is carried out by the inspection personnel of DNA laboratory at least once a year. 9.2.3 Blind test samples are made in a form similar to the samples of routine inspection cases. The organizer retains some samples to be tested for verification. 9.3 Qualification test report
9.3.1 Public test report includes the following contents: name of test organizer, identity of the tested person, start time of inspection, all original records, manufacturer and batch number of reagents used, typing conclusion, etc. 9.3.2 Testing report: Qualification blind test report is issued in the form of appraisal certificate. 9.4 Error correction
9.4.1 Management problem: When obvious mistyping is judged as management problem (wrong sample distribution, improper storage, etc.), the quality control procedures should be checked or improved against various quality control procedures. 9.4.2 System problems: When obvious mistyping is determined to be a system problem (instrument, reagent, experimental environment, etc.), all cases tested between the last qualified test and the current test should be checked immediately. After the cause of the error is found and corrected, all laboratory personnel should be informed to prevent similar errors from recurring.
9.4.3 Analytical test problems: When obvious mistyping is determined to be caused by the analytical tester himself, the tester should stop testing the case, and the DNA laboratory should appropriately check the cases tested between the last qualified test and the current test by the tester. After the problem is found and corrected, the tester can participate in additional proficiency tests and can only test cases after passing. 10 Laboratory verification
This type of verification is implemented by expert members of the special committee. The purpose is to evaluate the quality control level of the laboratory. The verification includes the contents specified in the previous article and is conducted at least once every two years. A report should be issued after the verification, including: verification date, verification items, verifiers, problems found and recommended improvement measures, and the next verification plan. 5
11 Laboratory Safety
GA/T3822002
DNA laboratories should comply with all government safety regulations, and at the same time, they should formulate special safety operation rules and make every member familiar with these regulations. There should be special procedures and records for the storage and disposal of chemicals. 63 Analytical test problems: When obvious mistyping is determined to be caused by the analyst himself, the tester should stop testing, and the DNA laboratory should appropriately verify the cases tested between the last qualified test of the tester and the current test. After finding the problem and correcting it, the tester can take additional proficiency tests and can only test cases after passing. 10 Laboratory verification
This type of verification is carried out by expert members of the special committee. The purpose is to evaluate the quality control level of the laboratory. The verification includes the contents specified in the previous article and is carried out at least once every two years. A report should be issued after the verification, including: verification date, verification items, verifiers, problems found and recommended improvement measures, next verification plan, etc. 5
11 Laboratory safety
GA/T3822002
DNA laboratories should comply with all government safety regulations, and at the same time, they need to formulate special safety operating rules and make each member familiar with these regulations. There should be special procedures and records for the storage and disposal of chemicals. 6
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