OBJECTIVESTo calibrate the national hepatitis B virus (HBV) DNA standard according to world health organization's standard material and prepare the national reference panel for HBV DNA reagents.

METHODSSera from blood donors and HBV patients were collected and detected by home-made HBV DNA PCR kits, HBsAg kits, and anti-HBc kits, and then confirmed by HBV DNA PCR kits produced by Roche in German, which was recognized by the world health organization. The stability of the panel was detected by acceleration method.

RESULTSThe convinced copies of the sensitivity samples were gotten by seven independent experiments, the coefficients of variation of logarithm of the copies of L0-L5 were all less than 15%. Regarding the national reference panel as the standard, the quality of most domestic HBV DNA PCR kits was improved, while part of the kits should be further qualified.

CONCLUSIONThe national reference panel for HBV DNA reagents is developed. It contains eight negative, nine positive sera and seven samples for sensitivity test

DNA, Viral ; standards ; Hepatitis B virus ; genetics ; Polymerase Chain Reaction ; Reference Standards ; Sensitivity and Specificity

Screening suitable reference genes is the premise of quantitative Real-time PCR(qRT-PCR)for gene expression analysis. To provide stable reference genes for expression analysis of genes in Aconitum vilmorinianum, this study selected 19 candidate re-ference genes(ACT1, ACT2, ACT3, aTUB1, aTUB2, bTUB, 18S rRNA, UBQ, eIF2, eIF3, eIF4, eIF5, CYP, GAPDH1, GAPDH2, PP2A1, PP2A2, ACP, and EF1α) based on the transcriptome data of A. vilmorinianum. qRT-PCR was conducted to profile the expression of these genes in the root, stem, leaf, and flower of A. vilmorinianum. The Ct values showed that 18S rRNA with high expression level and GAPDH2 with large expression difference among organs were not suitable as the reference genes. NormFinder and geNorm showed similar results of the expression stability of the other candidate reference genes and demonstrated PP2A1, EF1α, and CYP as the highly stable ones. However, BestKeeper suggested EF1α, ACT3, and PP2A1 as the top stable genes. In view of the different results from different softwares, the geometric mean method was employed to analyze the expression stability of the candidate re-ference genes, the results of which indicated that PP2A1, EF1α, and ACT3 were the most stable. Based on the comprehensive analysis results of geNorm, NormFinder, BestKeeper, and geometric mean method, PP2A1 and EF1α presented the most stable expression in different organs of A. vilmorinianum. PP2A1 and EF1α were the superior reference genes for gene expression profiling in different organs of A. vilmorinianum.
Aconitum ; Gene Expression Profiling ; Genes, Plant/genetics* ; Real-Time Polymerase Chain Reaction ; Reference Standards ; Reverse Transcriptase Polymerase Chain Reaction

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

BACKGROUNDSince October 1997, an international standard for hepatitis C virus (HCV) nucleic acid amplification technology assay, 96/790, has been available. We compared a series of lyophilized standards with known HCV RNA concentrations against the international standard in fluorescence quantitative PCR detection.

METHODSA series of lyophilized sera were calibrated by ROCHE COBAS AMPLICOR HCV Monitor test against the international standard and sent to various manufacturers to analyse the samples using their own kits. Then calibration curves from the series were compared with that obtained from the external standard calibration curve with the manufacture's series.

RESULTSThe standard calibration curve with the series of lyophilized serum showed an excellent correlation (R(2) > 0.98), slope and intercept that were similar to those from the manufacture's series. When the standard calibration curve from the series of lyophilized standards were used to define the values of the given sample, lower coefficients of variation between kits from different manufactures were obtained.

CONCLUSIONThe results showed that the lyophilized standards could be used to setup the standard calibration curve for clinical HCV RNA quantitative PCR detection.

Calibration ; Freeze Drying ; Hepacivirus ; genetics ; Humans ; Polymerase Chain Reaction ; standards ; RNA, Viral ; analysis ; World Health Organization

BACKGROUNDAs with many studies carried out in European countries, a quality assurance program has been established by the National Center for Clinical Laboratories in China (NCCL). The results showed that the external quality assessment significantly improves laboratory performance for quantitative evaluation of hepatitis C virus (HCV) RNA.

METHODSSerum panels were delivered twice annually to the clinical laboratories which performed HCV RNA detection in China. Each panel made up of 5 coded samples. All laboratories were requested to carry out the detection within the required time period and report on testing results which contained qualitative and/or quantitative test findings, reagents used and relevant information about apparatus. All the positive samples were calibrated against the first International Standard for HCV RNA in a collaborative study and the range of comparison target value (TG) designated as +/- 0.5 log.

RESULTSThe numbers of laboratories reporting on qualitative testing results for the first and second time external quality assessment were 168 and 167 in the year of 2003 and increased to 209 and 233 in 2007; the numbers of laboratories reporting on quantitative testing results were 134 and 147 in 2003 and rose to 340 and 339 in 2007. Deviation between the mean value for quantitative results at home in 2003 and the target value was above 0.5 log, which was comparatively high. By 2007, the target value was close to the national average except for the low concentrated specimens (10(3) IU/ml). The percentage of results within the range of GM +/- 0.5 log(10) varied from 8.2% to 93.5%. Some laboratories had some difficulties in the exact quantification of the lowest (3.00 log IU/ml) as well as of the highest viral levels (6.37 log IU/ml) values, very near to the limits of the dynamic range of the assays.

CONCLUSIONSThe comparison of these results with the previous study confirms that a regular participation in external quality assessment (EQA) assures the achievement of a high proficiency level in the diagnosis of HCV infection. During the 5-year external quality assessment, sensitivity and accuracy of detection in most of the clinical laboratories have been evidently improved and the quality of kits has also been substantially improved.

Hepacivirus ; genetics ; Humans ; Laboratories ; standards ; Polymerase Chain Reaction ; Quality Control ; RNA, Viral ; analysis ; Reagent Kits, Diagnostic

Siraitia grosvenorii is a traditional Chinese medicine also as edible food. This study selected six candidate reference genes by real-time quantitative PCR, the expression stability of the candidate reference genes in the different samples was analyzed by using the software and methods of geNorm, NormFinder, BestKeeper, Delta CT method and RefFinder, reference genes for S. grosvenorii were selected for the first time. The results showed that 18SrRNA expressed most stable in all samples, was the best reference gene in the genetic analysis. The study has a guiding role for the analysis of gene expression using qRT-PCR methods, providing a suitable reference genes to ensure the results in the study on differential expressed gene in synthesis and biological pathways, also other genes of S. grosvenorii.
Cucurbitaceae ; genetics ; RNA, Ribosomal, 18S ; genetics ; Real-Time Polymerase Chain Reaction ; methods ; Reference Standards

Screening the reference genes that were stably expressed under different light intensities for Viola yedoensis could provide reference for the related molecular research. In this study, 11 candidate reference genes were detected by RT-qPCR for tissues of V. yedoensis treated with different light intensities. Ge Norm, Norm Finder, Best Keeper, and Ref Finder website were used to comprehensively evaluate the reference genes, and verify the stability of the reference gene based on CAT1. Finally, the ideal reference gene was determined. The results showed that CYP, Actin, and SAMDC had small Ct value ranges and stable expression. Ge Norm demonstrated that CYP, SAMDC, and Actin were suitable reference genes. Norm Finder showed that the expression of α-TUB was the most stable. Best Keeper recommended CYP, Actin, and SAMDC as reference genes. Ref Finder assessed that SAMDC, CYP, α-TUB, and Actin had better stability, while GAPDH had the worst stability. The expression trend of CAT1 gene was consistent when calibrated with SAMDC, CYP, and Actin, while it was quite different from that calibrated with GAPDH. In summary, SAMDC, CYP, and Actin can be used as ideal reference genes for the gene expression profiling of V. yedoensis under different light intensities.
Gene Expression Profiling ; Real-Time Polymerase Chain Reaction ; Reference Standards ; Viola

In this study, the specific primers and probes of Panax quinquefolius were designed for a quantitative real-time PCR, and the rapid identification method of P. quinquefolius was established by optimizing conditions. The method was used to validate 43 samples of the traditional Chinese medicine,and the results showed that 22 samples of P. quinquefolius were identified accurately. The limit of detection of the method can be reach to 1×10⁻⁴ ng. The method is accurate, fast, sensitive and specifically.
DNA Primers ; DNA Probes ; Drugs, Chinese Herbal ; standards ; Panax ; genetics ; Real-Time Polymerase Chain Reaction

A multiplex PCR method was developed to detect the main pathogens of Qinghai Tibetan sheep endometritis. First, the genomes of five standard bacterial strains were extracted and specific primers were selected; the multiplex PCR method was established by using the genome of the standard strain as a template. The samples were collected by sterile cotton swab from Tibetan sheep uterus, and then placed in LB medium and numbered. After 48 h, the genomes of cultured bacteria were extracted and detected by single PCR method, then the positive samples were recorded. The positive samples detected by single PCR were selected for multiplex PCR detection and recorded again. The coincidence rate between these two methods was calculated to measure the accuracy of multiplex PCR. In order to identify the species of the pathogen, 30 positive samples verified by single and multiplex PCR were randomly selected for bacterial isolation and identification. In the 600 samples, the infected ratio of Streptococcus agalactiae (GBS) was 47.33%, Escherichia coli 34.83%, Staphylococcus aureus 6.5%, Salmonella and Trueperella pyogenes were negatively detected. Among the positive samples detected by multiplex PCR, the positive ratio of GBS was 45.50%, E. coli 33.50%, S. aureus 6.5%. Comparison of two detection results, Multiplex PCR detection coincidence rate is more than 95%. The isolated pathogens were identified as E. coli, GBS and S. aureus, which was consistent with the results of two methods. The multiplex PCR method was successfully established and the main pathogens of endometritis in Qinghai Tibetan sheep were GBS, E. coli and S. aureus.
Animals ; Bacteria ; genetics ; isolation & purification ; Bacteriological Techniques ; methods ; Endometritis ; microbiology ; veterinary ; Female ; Multiplex Polymerase Chain Reaction ; standards ; Polymerase Chain Reaction ; veterinary ; Sensitivity and Specificity ; Sheep ; Sheep Diseases ; microbiology ; Tibet

OBJECTIVETo establish the controls for allele detection of blood groups s and Ok(a). A multiplex PCR method for the detection of three blood group antigens Fy(a), s and Ok(a) was developed and used to investigate the distribution of these blood groups in Chinese random blood donors.

METHODSPolymerase chain reaction (PCR)-based, gene site-directed mutagenesis (SDM) technique were used to make site-directed mutagenesis for the single nucleotide polymorphism (SNP) sites of the blood group alleles (the 153 C/T point mutation of the GYPB gene, and the 274 G/A point mutation of the BSG gene) as controls for allele detection. Sequence specific primers were designed according to the SNP sites of alleles of blood group antigens Fy(a), s and Ok(a). A multiplex PCR system was developed and 438 random donor samples were screened for the blood group antigens Fy(a), s and Ok(a).

RESULTSThe controls for alleles in blood groups s and Ok(a) were successfully made with the SDM technique, a multiplex PCR system was set up and successfully used to analyze the genotypes of three blood group antigens Fy(a), s and Ok(a). Two Fy(a-) samples were detected in the 438 samples, no s- and Ok(a-) sample was found.

CONCLUSIONThe PCR-based SDM technique can be used to obtain the unavailable controls in blood group genotyping. The multiplex PCR technique established in this study is an efficient genotyping method for blood groups Fy(a), s and Ok(a).

Alleles ; Base Sequence ; Blood Donors ; Blood Group Antigens ; genetics ; Blood Grouping and Crossmatching ; standards ; Genotype ; Humans ; Mutagenesis, Site-Directed ; Polymerase Chain Reaction ; standards ; Polymorphism, Single Nucleotide ; Reference Standards