Study of The Y-STR Multiplex Microfluidic Chip Rapid Amplification System
Objective At present,the matching reagents of commercially available rapid DNA instruments based on microfluidics chip technology are autosome short tandem repeat(STR)individual identification reagents.The non-recombining part of the human Y chromosome is widely used in forensic DNA analysis,particularly in cases where standard autosomal DNA profile is uninformative.Y-STR loci are useful markers to identify males and male lineages in forensic practice.In order to achieve rapid and fully integrated detection of Y-STR loci,this study constructed the RTyper Y27 microfluidic chip rapid detection system and validated the performance of this system.Methods The system was verified and evaluated by sensitivity,success rate,typing accuracy,peak height balance,sizing precision and accuracy,mock case sample tests,mixture detection ability,and inhibition tolerance.Results Complete Y-STR profiles can be obtained when the template amount of DNA standard 9948 was ≥8 ng,the number of blood cards was ≥3 pieces,and the number of oral swab scrapings was≥7 times.The success rate of fully integrated detection was 91.52％,and the concordance rates was 99.74％for 165 testing samples.The success rate of 115 blood spots in these samples was 90.43％,with a typing accuracy of 99.65％,the success rate of 50 buccal swabs was 94％,with a typing accuracy of 99.92％.There was no significant difference in typing accuracy between blood spots and buccal swab samples.The peak height ratio between different fluorescence channels was 89.81％.The standard deviation of allelic ladder for 10 runs was within 0.5 bp.The size differences between allele and corresponding allele in allelic ladder was within 0.5 bp.The maximum precision CV values within and between batches were 0.48％and 0.68％,respectively,which were lower than 15％.These data indicate that the system has good accuracy and precision.The system was capable of accurately typing oral swabs,blood cards,saliva cards,cigarette butts,blood swabs and seminal stains.Complete Y-STR profiles can be obtained and distinguish at the 1:3 ratio of minor and major contributors in artificial male DNA mixtures.Complete Y-STR genotyping can be obtained under the interference of inhibitors,such as different concentrations of humic acid(50-400 mg/L),indigotin(20-100 nmol/L)and hemoglobin(100-500 μmol/L).Conclusion In this study,the RTyper Y27 microfluidic chip rapid amplification system is combined with the Quick TargSeq 1.0 integrated system,and the Y-STR profile can be obtained in approximately 2 h.Through a series of verification experiments,the results show that the system has good repeatability,accuracy and stability,can meet the on-site Y-STR detection requirements,and can be used in forensic practice.
forensic biological evidencemicrofluidic chipY-chromosomal short tandem repeat
万方数据
维普
