Analysis method of mixed DNA map

Abstract

The invention provides an analysis method of a mixed DNA map, and belongs to the technical field of forensic genetics and forensic physical evidence. The method comprises the following steps: reading first-generation DNA STR map data and related parameters generated by capillary electrophoresis; generating a candidate genotype set of each gene locus by using the map data and the related parameters; determining a sampling interval of prior distribution of the preset sample parameters by using the atlas data and the related parameters; according to the determined sampling interval of the prior distribution of the preset sample parameters, sampling the candidate genotype set and the posterior distribution of the sample parameters by using an MCMC algorithm; and performing statistics on preset related indexes by using the candidate genotype set obtained by sampling and the posterior distribution of the sample parameters, and performing mixed DNA atlas analysis to obtain various analysis results. According to the method, first-generation DNA STR atlas data can be analyzed, atlas analysis is more objective, meanwhile, all input gene loci are split, and the splitting accuracy is high.

Description

technical field [0001] The invention relates to the technical fields of forensic genetics and forensic physical evidence, in particular to an analysis method of a mixed DNA map. Background technique [0002] Due to its high degree of individual specificity and objectivity, DNA testing has become an important basis for the public security organs to investigate and solve cases, and the judicial system for conviction and sentencing. The mainstream technology of DNA map analysis in physical evidence in the current forensic DNA laboratory is to perform STR (short tandem repeat sequence, short tandem repeat sequence, Short Tandem Repeat) genetic marker test, if the DNA sample contains the DNA of two or more people, a mixed DNA profile will be obtained. [0003] In recent years, with the continuous update and development of forensic DNA testing instruments and reagents, the sensitivity of DNA testing has become higher and higher, and the number of mixed DNA detected in case-site s...

AI Technical Summary

Problems solved by technology

[0007] 1. Manual analysis requires experienced forensic DNA experts, which is slow and labor-intensive;

[0008] 2. Manual analysis is highly subjective. Different forensic laboratories, different forensic workers in the same forensic laboratory, and the same forensic worker may split different single-person samples from the same mixed DNA sample at different times. , it is also possible to make a different judgment on whether a given individual is included in the mixed DNA, which seriously damages the objectivity of the DNA evidence;

[0009] 3. Manual analysis can only analyze some simple mixed samples of two people, but cannot analyze complex mixed samples of two or more people;

[0010] 4. Manual analysis can only use part of the information in the mixed DNA map, and the efficiency of splitting is limited. In most cases, only a few loci can be split

[0011] 5. Manual splitting cannot provide quantitative indicators to measure the possibility of whether the suspect's DNA is included in the map, so it cannot be used as physical evidence in forensic science

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