Objective To evaluate the efficiency of REPLI-g® Single Cell Kit for sample DNA amplification, and explore its application value in forensic trace DNA amplification. Methods Three DNA extraction kits were selected to extract DNA from peripheral blood of 10 unrelated individuals. The DNA yield and purity of the three DNA extraction kits were compared. According to the results of comparison, one DNA sample was selected to concentrate and dilute, then used as the initial sample of whole genome amplification （WGA）. REPLI-g® Single Cell Kit was used to amplify the initial sample at the whole genome level. The amplification yield and amplification times were calculated, and the distribution of DNA fragments was detected by agarose gel electrophoresis. Goldeneye® DNA ID System 20A Kit was used to perform the STR typing of the initial sample and DNA samples amplified at the whole genome level to evaluate the performance of REPLI-g® Single Cell Kit in trace DNA amplication in terms of purity and yield as well as the success rate of STR typing. Results After comparison, one DNA sample was selected from QIAsymphony® DNA Investigator® Kit extracts to concentrate and dilute as the initial sample of WGA. After amplifying the whole genome of a series of initial samples by REPLI-g® Single Cell Kit, the lowest average of amplification yield reached 8.77×103 ng, while the average of the corresponding amplification times reached 1.40×106. DNA fragments were large and concentrated. The STR typing success rate of WGA samples became lower with the decrease of initial samples used, but when the amount of samples was lower than 0.5 ng, the STR typing success rate of samples after DNA WGA was higher than that of samples without DNA WGA. Conclusion REPLI-g® Single Cell Kit can increase the yield of template DNA. Especially for trace DNA, the STR typing success rate can be improved to a certain extent.
DNA ; DNA Fingerprinting ; Humans ; Microsatellite Repeats ; Nucleic Acid Amplification Techniques/standards* ; Sequence Analysis, DNA/methods*

OBJECTIVETo analyze the possible reason for HLA-C allele dropout in routine sequence-based typing (SBT) and improve the accuracy of HLA-C SBT test.

METHODSA total of 620 randomly selected samples from healthy voluntary blood donors in Shenzhen were typed at HLA-C locus by sequence-based typing using the AlleleSEQR HLA-C plus sequence-based typing kit. Samples with no full match result were subjected to cloning and haplotype sequencing of the full-length HLA-C gene. If no novel mutations were found, samples were then retyped, using our self-designed PCR primer pair and PCR conditions replacing the AlleleSEQR HLA-C PCR reagents in the PCR set-up procedure so as to analyze the potential reasons for causing abnormal SBT result.

RESULTSIn the 620 samples typed at HLA-C locus using the AlleleSEQR HLA-C SBT commercial kit, 5 samples with no full match result were identified. The closest genotype showed one nucleotide mismatch with many different allele groups at different nucleotide position. Based on the PCR-SBT nucleotide sequence, heterozygous nucleotides were determined only in exon 4, whereas the nucleotides in exon 2 and 3 were all homozygotes. The results showed that HLA-Cw*0706 allele dropout existed in all the 5 samples with abnormal SBT results initially identified by AlleleSEQR HLA-C SBT kit, no novel mutation was found.

CONCLUSIONThe results indicate that the PCR primer pair incompatible with DNA template may result in allele dropout in HLA-C SBT test. Based on the characterization of HLA-C full-length, it is essential to develop HLA-C SBT kit suitable for Chinese population in the future.

Alleles ; Amino Acid Sequence ; Base Sequence ; DNA Fingerprinting ; methods ; standards ; HLA-C Antigens ; genetics ; Humans ; Molecular Sequence Data ; Mutation ; Sequence Analysis, DNA ; methods ; standards

Characterized reference materials (RMs) are needed for clinical laboratory test development and validation, quality control procedures, and proficiency testing to assure their quality. In this article, we review the development and characterization of RMs for clinical molecular genetic tests. We describe various types of RMs and how to access and utilize them, especially focusing on the Genetic Testing Reference Materials Coordination Program (Get-RM) and the Genome in a Bottle (GIAB) Consortium. This review also reinforces the need for collaborative efforts in the clinical genetic testing community to develop additional RMs.
Genetic Testing/*standards ; High-Throughput Nucleotide Sequencing/standards ; Humans ; Public Relations ; Quality Control ; Reference Values ; Sequence Analysis, DNA/standards

The rapid development of high-throughput sequencing technologies has led to a dramatic decrease in the money and time required for de novo genome sequencing or genome resequencing projects, with new genome sequences constantly released every week. Among such projects, the plethora of updated genome assemblies induces the requirement of version-dependent annotation files and other compatible public dataset for downstream analysis. To handle these tasks in an efficient manner, we developed the reference-based genome assembly and annotation tool (RGAAT), a flexible toolkit for resequencing-based consensus building and annotation update. RGAAT can detect sequence variants with comparable precision, specificity, and sensitivity to GATK and with higher precision and specificity than Freebayes and SAMtools on four DNA-seq datasets tested in this study. RGAAT can also identify sequence variants based on cross-cultivar or cross-version genomic alignments. Unlike GATK and SAMtools/BCFtools, RGAAT builds the consensus sequence by taking into account the true allele frequency. Finally, RGAAT generates a coordinate conversion file between the reference and query genomes using sequence variants and supports annotation file transfer. Compared to the rapid annotation transfer tool (RATT), RGAAT displays better performance characteristics for annotation transfer between different genome assemblies, strains, and species. In addition, RGAAT can be used for genome modification, genome comparison, and coordinate conversion. RGAAT is available at https://sourceforge.net/projects/rgaat/ and https://github.com/wushyer/RGAAT_v2 at no cost.
Genome ; Genomics ; High-Throughput Nucleotide Sequencing ; methods ; standards ; Humans ; Reference Standards ; Sequence Analysis, DNA ; methods ; standards ; Software

Normalization of the data of cDNA microarray is an obligatory step during microarray experiments due to the relatively frequent non-specific errors. Generally, normalization of microarray data is based on the null hypothesis and variance model. In the Yang's model (Yang et al., 2001), at least two types of noises are included. The one is additive noise and the other is multiplicative noise. Usually, background is considered as one of additive noise to the signal and the variation between the signal pixels is the representative multiplicative noise. In this study, the relation between the signal (spot intensity minus background intensity) and background was observed and the influence of background on normalization as a representative additive factor was investigated. Although the relation has not been considered as a factor affecting the normalization, it could improve the accuracy of microarray data when the normalization was carried out considering signal/background ratio. The background dependent normalization decreased the number of genes whose expression levels were changed significantly and it could make their distribution more consistent through the whole range of signal intensities. In this study, printing pin dependent normalization was also carried out regarding the printing pin as a representative multiplicative noise. It improved the distribution of spots in the Cy3-Cy5 scatter plot, but its effect was slight. These studies suggest that there are some influences of the signals on the local backgrounds and they must be considered for the normalization of cDNA microarray data.
Carbocyanines ; DNA, Complementary/*analysis/genetics ; Gene Expression Profiling/*methods/*standards ; Linear Models ; Oligonucleotide Array Sequence Analysis/*methods/*standards ; Reference Standards ; Reproducibility of Results ; Sensitivity and Specificity

The resource authentication is required for quality assurance and control of Chinese medicine. This review provides an informative introduction to molecular methods used for authentication of Chinese medicinal materials. The technical features of the methods based on sequencing, polymerase chain reaction (PCR) and hybridization are described, merits and demerits and development of the molecular methods in identification of Chinese medicinal materials are discussed.
Biometric Identification ; methods ; Medicine, Chinese Traditional ; standards ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVEThe quality of microarray data influences the accuracy of comparative genomic analyses to a large extent. To ensure that the results obtained by using an in situ synthesized microarray are accurate, data quality is to be assessed by evaluating the melting temperature (Tm) of probes, probability of false synthesis rates, and fragmentation of labeled targets.

METHODSDNA from the Yersinia pestis vaccine strain EV76 was used for microarray analyses. Microarray results were confirmed by PCR. Statistical and bioinformatics methods were employed to perform microarray data analyses and evaluation.

RESULTSCorrelation coefficients of the three datasets were above 0.95 after two-time stripping and hybridization with a labeled DNA with the size of fragmentation being 200 bp - 2 kb, which showed that the hybridization results were highly reproducible. Correlation coefficients were lower with the values ranging from 0.87 to 0.92 between the datasets generated from hybridization with different sizes of the labeled DNA fragment. For the relationship between Tm and signal intensity, there was a different distribution of Tm in the lowest 300 or 3,000 probes with a range of 70 °C-72 °C and the highest 300 or 3,000 probes with a range of 72 °C-74 °C.

CONCLUSIONThe results of this study suggest that the initial microarray design may affect the accuracy of final analyses and that the probe Tm and the size of the labeled fragment may be the two factors of the greatest importance.

Cluster Analysis ; Comparative Genomic Hybridization ; methods ; standards ; DNA Fragmentation ; DNA, Bacterial ; genetics ; Genome, Bacterial ; Oligonucleotide Array Sequence Analysis ; methods ; standards ; Polymerase Chain Reaction ; Reproducibility of Results ; Yersinia pestis ; genetics

OBJECTIVEPoisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China.

METHODSSeventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes (matK, rbcL, and ITS) were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment (PWG) distance, and Tree-Building were tested for discrimination power.

RESULTSThe primer universality of all the three markers was high. Except in the case of ITS for Hemerocallis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method.

CONCLUSIONDNA barcoding technique provides us a fast tool for clinical identification of poisonous plants in China. We suggest matK, rbcL, ITS used in combination as DNA barcodes for authentication of poisonous plants.

China ; DNA Barcoding, Taxonomic ; standards ; DNA Primers ; genetics ; DNA, Intergenic ; genetics ; Plant Proteins ; genetics ; Plants, Toxic ; classification ; genetics ; Ribulose-Bisphosphate Carboxylase ; genetics ; Sequence Analysis, DNA ; Species Specificity

OBJECTIVETo study the correlation between ITS sequence of Arctium lappa and Fructus Arctii quality of different origin.

METHODThe samples of Fructu arctii materials were collected from 26 different producing areas. Their ITS sequence were determined after polymerase chain reaction (PCR) and quality were evaluated through the determination of arctiin content by HPLC. Genetic diversity, genotype and correlation were analyzed by ClustalX (1.81), Mage 4.0, SPSS 13.0 statistical software.

RESULTITS sequence of A. was obtained from 26 samples, and was registered in the GenBank. Corresponding arctiin content of Fructus arctii and 1000-grain weight were determined. A. lappa genotype correlated with Fructus arctii quality by statistical analysis.

CONCLUSIONThe research provided a foundation for revealing the molecular mechanism of Fructus arctii geoherbs.

Arctium ; chemistry ; genetics ; Computational Biology ; DNA, Ribosomal Spacer ; genetics ; Drugs, Chinese Herbal ; standards ; Furans ; analysis ; Genotype ; Glucosides ; analysis ; Polymorphism, Genetic ; genetics ; Quality Control ; Sequence Analysis, DNA ; Software

OBJECTIVETo provide basis for quality control of Zijingpi, DNA identification was used based on NCBI nucleotide database analysis.

METHODFirstly, total DNA of Zijingpi was extracted. Secondly, the ITS sequence was amplified by PCR with universal primer of ITS and PCR products was directly sequenced after purification. Finally, ITS sequence similarity and phylogenetic tree were used for identification.

RESULTThe ITS sequence information of the mainstream commercial drugs of Zijingpi was obtained.

CONCLUSIONIt is firstly reported that the mainstream commercial drugs of Zijingpi was the bark of Schisandra sphenanthera.

DNA, Plant ; genetics ; Databases, Nucleic Acid ; Drugs, Chinese Herbal ; chemistry ; standards ; Molecular Sequence Data ; Phylogeny ; Quality Control ; Schisandra ; classification ; genetics ; Sequence Analysis, DNA