Development and validation of real-time fluorescence quantitative PCR method for murine virus / 中国生物制品学杂志

@#Objective To develop and validate the real-time fluorescent quantitative PCR(Q-PCR)method for the detection of 8 murine viruses. Methods The specificity,sensitivity and precision of the Q-PCR method were verified by four laboratories,and the virus simulated contamination test and blind sample detection were carried out simultaneously,of which the detection results were compared. The Q-PCR method was used to detect 26 batches of monoclonal antibody cell lines for SARS-CoV-2 vaccine production and 15 batches of other products of murine origin. Results The Q-PCR method used for detecting 8 kinds of murine viruses had no cross reaction with the same family and genus or other murine viruses. Except the sensitivity of laboratory 2 to ectromelia virus(EctV/Mouse Pox,MPV)was 2 × 10~2copies/μL,the sensitivity of laboratory 2 to other 7 viruses and 3 other laboratories to 8 murine viruses was 2 × 10~1copies/μL. Except the inter-assay CV of the copy number of mouse adenovirus(MAdV)detected by laboratory 3 was 37. 58%,the intra-assay and inter-assay CVs of the Ct and copy number of other 7 viruses detected by laboratory 3 and those of 8 viruses detected by other 3 laboratories were all less than 25%.The sensitivity of virus simulated contamination test met the parameter requirements. The coincidence rate of blind sample detection results by 4 laboratories was 100%. All the 26 batches of monoclonal antibody cell lines for SARS-CoV-2 vaccine production and 15 batches of other murine derived products were negative for 8 murine viruses. Conclusion Q-PCR method for murine virus has good specificity,sensitivity and precision,and can be used for the detection of murine derived biological products.

Selection and validation of reference genes for quantitative real-time PCR analysis in Paeonia veitchii / 中国中药杂志

Paeonia veitchii and P. lactiflora are both original plants of the famous Chinese medicinal drug Paeoniae Radix Rubra in the Chinese Pharmacopoeia. They have important medicinal value and great potential in the flower market. The selection of stable and reliable reference genes is a necessary prerequisite for molecular research on P. veitchii. In this study, two reference genes, Actin and GAPDH, were selected as candidate genes from the transcriptome data of P. veitchii. The expression levels of the two candidate genes in different tissues(phloem, xylem, stem, leaf, petiole, and ovary) and different growth stages(bud stage, flowering stage, and dormant stage) of P. veitchii were detected using real-time fluorescence quantitative technology(qRT-PCR). Then, the stability of the expression of the two reference genes was comprehensively analyzed using geNorm, NormFinder, BestKeeper, ΔCT, and RefFinder. The results showed that the expression patterns of Actin and GAPDH were stable in different tissues and growth stages of P. veitchii. Furthermore, the expression levels of eight genes(Pv-TPS01, Pv-TPS02, Pv-CYP01, Pv-CYP02, Pv-CYP03, Pv-BAHD01, Pv-UGT01, and Pv-UGT02) in different tissues were further detected based on the transcriptome data of P. veitchii. The results showed that when Actin and GAPDH were used as reference genes, the expression trends of the eight genes in different tissues of P. veitchii were consistent, validating the reliability of Actin and GAPDH as reference genes for P. veitchii. In conclusion, this study finds that Actin and GAPDH can be used as reference genes for studying gene expression levels in different tissues and growth stages of P. veitchii.

Establishment and application of detection method for interferon stimulated genes expression in children / 中华检验医学杂志

Objective:To establish the detection method for the interferon stimulated genes(ISGs), calculate the cut-off value and test it in clinical practice.Methods:Patients with type I interferonopathies who were admitted to Peking Union Medical College Hospital from November 2017 to September 2021 were chosen as the disease group, and healthy children were included as the control group. A total of 18 children were in the disease group, including 8 males and 10 females, with a median age of 8.5 years for the first test. From them 25 blood specimens were collected. A total of 28 healthy children, aged 1 to 18 years, with a median age of 10.5 years, including 15 males and 13 females, were included in the control group. Blood samples of 34 controls and 18 interferonopathies patients were collected, then total RNA extraction and cDNA synthesis were performed. Real-time quantitative polymerase chain reaction assays were run in duplicate to measure the expression of six ISGs: interferon induced protein with tetratricopeptide repeats 1 (IFIT1), interferon α inducible protein 27 (IFI27), interferon induced protein 44 like (IFI44L), interferon stimulated genes 15 (ISG15), sialic acid binding Ig like lectin 1 (SIGLEC1), and radical S-adenosyl methionine domain containing 2 (RSAD2). The relative abundances of each target transcript was normalized to the expression level of β-Actin and OAZ. The median fold change of the six ISGs was used to create an interferon score (IS) for each individual. Samples with abnormal expressions were removed and the cDNA mix of the remaining samples was used as a calibrator to calculate the IS. We define an abnormal IS as being greater than+2 standard deviations above the mean of controls. Differences in IS between groups were compared using t-test or Mann-Whitney U-test. Results:The mean IS of controls was 1.046, standard 0.755, and the cut-off value was 2.556. A total of 25 samples from 18 interferonopathies patients were tested. The mean value was 27.010 with a 15/18 abnormality rate. Compared with the control group, IS in patients was significantly higher, t=4.247( P=0.000 1). The accuracy, precision, sensitivity, and specificity were 91.30% (42/46), 7.47%(0.084/1.124), 15/18, and 96.43% (27/28), respectively. Conclusion:This study provides a new and reliable method for clinical screening and dynamic monitoring of type Ⅰ interferonopathies by detecting ISGs expression and creating an IS.

Significance of serum circRNA hsa_circ_0000437 in the auxiliary diagnosis and prognosis of gastric cancer / 中华检验医学杂志

Objective:To investigate the expression of hsa_circ_0000437 in the serum of patients with gastric cancer and its clinical value.Methods:The serum samples from 80 patients (57 males and 23 females) with pathologically confirmed gastric cancer (GC), 50 gastric benign disease (28 males and 22 females) and 80 healthy controls (46 males and 34 females) were collected from October 2018 to December 2020 in Affiliated Hospital of Nantong University.Serum samples from 35 of 80 gastric cancer patients after operation were collected. The expression of serum hsa_circ_0000437 was determined by real-time fluorescent quantitative PCR (RT-qPCR). Serum carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA 199) and carbohydrate antigen 724 (CA724) were determined by chemiluminescence method.Comparisons of serum hsa_circ_0000437 between groups were performed by Mann-Whitney U test.The correlation between serum expression of hsa_circ_0000437 in gastric cancer patients and its clinical pathological characteristics was performed by χ 2 test.Receiver operating characteristic (ROC) curve and the area under the curve of ROC (AUC) were used to evaluate their diagnosis efficiency. Kaplan-Meier survival curve analysis was used to analyze the relationship between the expression level of serum hsa_circ_0000437 and the prognosis of patients. Results:The relative expression of hsa_circ_0000437 in GC, gastric benign disease, healthy controls were 2.252 (1.235, 4.765), 1.598(1.139, 1.982) and 1.000 (0.818, 1.385) respectively.The relative expression of hsa_circ_0000437 in GC was significantly higher than that in gastric benign disease ( P<0.001) and healthy controls ( P<0.001). The difference between gastric benign disease and healthy controls was also statistically significant ( P<0.001).The differences of serum hsa_circ_0000437 expression in GC patients between T stage, N stage, and tumor differentiation were statistically significant. The AUC of hsa_circ_0000437, CEA, CA199 and CA724 in GC patients were 0.863, 0.619, 657 and 0.608 respectively compared with healthy controls. The AUC of above four-parameter panel was 0.892 and the sensitivity was up to 97.5% (78/80). Kaplan-Meier survival curve showed that the overall survival rate of patients with high serum hsa_circ_0000437 expression was significantly lower than that of patients with low expression ( P=0.008). Conclusion:Serum hsa_circ_0000437 could be a biomarker for the auxiliary diagnosis and prognosis of GC.

Establishment and preliminary application of a joint detection method for transplantation-associated infection pathogens / 中国输血杂志

【Objective】 To investigate the effectiveness of multilink real-time fluorescence quantitative PCR (qPCR) in the detection of common pathogens in transplantation. 【Methods】 The primers of the qPCR detection system were designed for 24 common infectious pathogens after clinical transplantation, and the standard plasmids of each pathogen were used to verify the qPCR reaction.After the primer probe effect and concentration of each pathogen reaction system in this experiment was optimized, the sensitivity, correlation coefficient (R2) and amplification efficiency (E) of qPCR method were analyzed and confirmed.Twenty-two samples from patients, who underwent liver and kidney transplantation in transplant ICU of Sichuan Provincial People′s Hospital, were used to verify the application of the detection system.The total nucleic acid of 100 μL was extracted from each individual and divided into two aliquots, which were detected by multi-link qPCR reaction system and analyzed by high-throughput sequencing method (NGS). At the same time, samples (2 mL each) were taken from the transplanted patients for microbial culture.The results of the three detection methods were compared, and the NGS method was taken as the gold standard to analyze the positive detection rate of the multi-link qPCR method and its difference with the culture method and NGS. 【Results】 The lower limit of qPCR detection for 24 pathogens in the established qPCR detection system was 101cp/μL(R2>0.99), with the positive rate of pathogens at 59.1% (13/22), showing significant difference versus microbial culture (18.2%, 4/22)(P<0.05), but not versus NGS (63.6%, 14/22)(P>0.05). Percentage of pathogens detected was as follows: human herpetic virus type 6 (HHV-6) 30.8% (4/13), cytomegalovirus (HCMV) 23.1% (3/13), Epstein-Barr virus (EBV) 23.1% (3/13), human parvovirus B19 15.4% (2/13), Haemophilus influenzae (Hin) 15.4% (2/13), Enterococcus faecium (EFM) 15.4% (2/13), Clostridium difficile 15.4% (2/13), Escherichia coli 7.7% (1/13), Stenotrophomonas maltophilia (Sma) 7.7% (1/13), Klebsiella pneumoniae (Kpn) 7.7% (1/13), Enterococcus faecalis (Efa) 7.7% (1/13) and Streptococcus pneumoniae (Spn) 7.7% (1/13). The consistency rate of pathogens detected by the three methods was 32% (7/22), among which the consistency rate of multi-link qPCR with NGS method was 59% (13/22), and multi-link qPCR with microbial culture was 41% (9/22). 【Conclusion】 Compared with the microbial culture, the multi-link qPCR method demonstrated high sensitivity, accurate quantification, short time and low cost for the detection of common pathogens in clinical transplantation.Multi-link qPCR combined with NGS and microbial culture is helpful to quickly predict the pathogen infection status of patients after transplantation.

Development and application of real-time qPCR assay for detecting Sendai virus gene copy number / 中华实验和临床病毒学杂志

Objective@#To develop a real-time quantitative PCR (qPCR) assay for detecting Sendai virus gene copy number.@*Methods@#The recombinant plasmid was constructed and a reference used to establish the real-time qPCR method with the TaqMan probe and verified for reproducibility and sensitivity.@*Results@#The linear range of the developed real-time qPCR assay was 1.024 × 103 ~5 × 1010 copies/μl, with an R2 value of more than 0. 99. The standard recovery of the tested samples was 84.56%~119.48%.@*Conclusions@#Compared with traditional hernagglutination assay for particle number detection, this method has higher sensitivity, better repeatability and high quantitative accuracy. It can be used for the detection of particle number of vaccine with sendai virus as the carrier, so as to detect the specific activity of vaccine products.

Real-time fluorescent quantitative PCR detection of key enzyme genes expression of alkaloid biosynthesis promoted by endophytic fungal elicitor in Sophora alopecuroides / 中草药

Objective To establish a method of detecting the expression of Lysine decarboxylase (LDC) -a key enzyme for the synthesis of alkaloid in the host promoted by the endophytic fungal elicitor of Sophora alopecuroides by using real-time fluorescence quantitative PCR (qRT-PCR). Methods Target gene primers QLDC-F/QLDC-R and reference gene primers Lectin-F/Lectin-R were designed according to LDC and Lectin gene sequences of S. alopecuroids; Five-fold gradient dilution of cDNA was used as the standard sample for the construction of the standard curve of target gene and the reference gene. Reaction system and reaction conditions of qRT-PCR were optimized, and the sensitivity of semi-quantitative PCR and qRT-PCR were analyzed and compared. Under different eliciting time of endophytic fungal elicitors NDZKDF13 of S. alopecuroides, the content of oxymatrine in the host was determined by HPLC, the expression of LDC gene was detected by qRT-PCR, and the relationship between LDC gene expression and the accumulation of OMA was analyzed. Results The results of qRT-PCR were better when the cDNA content in the system was 200 ng/μL and the annealing temperature was 61 ℃. The standard curve of the target gene and the reference gene was constructed, in which the cycle threshold and template concentration showed a good linear relationship, the amplification efficiency was above 99%, and the sensitivity was 25 times that of semi-quantitative PCR. Under the induction effect of endophytic fungal elicitor NDZKDF13, expression of host LDC gene reached the peak on the 6th day, which was 25.58 times that of the control. The increase of OMA content lagged the change of the LDC gene expression and reached the highest amount on the 9th day after the induction. Conclusion The qRT-PCR technique was successfully applied to the functional gene research of S. alopecuroides. Through the optimization of various conditions, a platform for accurate and simple detection of functional gene expression in S. alopecuroides was established.

Effects of transport and storage conditions on the nucleic acid detection for three kinds of mouse RNA viral samples / 中国比较医学杂志

Objective To analyze the effect of transport and storage conditions on the detection of pathogenic nucleic acid MHV, Reo-3, MNV in laboratory mouse cecal contents samples. Methods MHV, Reo-3 and MNV were mixed with mouse cecal contents and used as reference samples,respectively. They were placed in the lysis buffer of RNA extraction reagent(buffer AVL)or normal saline, and stored at 4℃ and room temperature(22℃-25℃). RNA of these samples was extracted at 1,2,3,7,and 14 days. Then the amount of nucleic acid in samples was detected by real-time fluorescence quantitative PCR. Results A greater decrease of the amount of nucleic acid was observed when the samples were placed in normal saline than that kept in buffer AVL. The amount of nucleic acid in samples stored at 4℃ was found to be higher than that stored at 25℃ room temperature. The amount of nucleic acid in the samples which were kept in buffer AVL at 4℃ for 3 days was higher than 50%,still detectable in the samples kept for 7 days,and undetectable at 14 days. Conclusions Mouse cecal content samples are preferably stored in the lysis buffer of RNA extraction reagent and transported at 4℃ for the detection of MHV, Reo-3, and MNV nucleic acid. It is better to complete the detection test within 3 days.

Establishment and application of a TaqMan real-time fluorescence quantitative PCR for detection of tree shrew adenovirus(TAV) / 中国比较医学杂志

Objective To establish a quick and accurate method for detection of tree shrew adenovirus(TAV) using TaqMan real-time fluorescence quantitative PCR. Methods Based on the published TAV genome sequence, a 3' conserved sequence was used to design specific probe primers. A standard curve was prepared using a recombinant plasmid containing the target gene fragment. A real-time fluorescence quantitative PCR method was established for detecting TAV based on TaqMan probe. Results The detection method was specific and was not cross-reactive with other common pathogens. The detection limit of the method was 3.7 copies/μL,showing a high sensitivity. The correlation coefficient was 0.998, and the efficiency was 95.7%. The amplification result showed a fine linear relationship,and the repeatability test effect was good. Conclusions The TAV real-time quantitative PCR detection method based on TaqMan probe has been successfully established. It has high sensitivity and reproducibility and can be applied to early detection of TAV infection.

Comparative study on three methods of nucleic acid extraction and three kinds of real-time fluorescence quantitative PCR instrument / 中华实验和临床病毒学杂志

Objective@#To explore the differences among three methods of nucleic acid extraction and three kinds of real-time fluorescence quantitative PCR instrument.@*Methods@#Twenty-five respiratory virus nucleic acid and 25 enterovirus nucleic acid positive samples were with selected at random and nucleic acids were extracted by using three methods (method A, B, and C). The results among different methods were analyzed by randomized block design. 25 respiratory viral nucleic acid positive specimens and enterovirus nucleic acid positive samples were detected by using three kinds of real-time fluorescence quantitative PCR instrument (instrument A, B, and C). The results among different instruments were analyzed by randomized block design.@*Results@#There was a significant difference among three methods of nucleic acid extraction in results(χ2=42.9162, P<0.001), in which method A and C had not significant difference(Z=0.837, P=0.3816>0.05), while method A vs. B, B vs. C were significantly different(Z=7.025, P<0.001; Z=7.9, P<0.001). There was also a significant difference among three kinds of real-time fluorescence quantitative PCR instrument in results(χ2=23.773, P<0.001), in which instrument B and C had no significant difference(Z=0.75, P=0.4533>0.05), while instrument A vs. B, A vs. C were significantly different(Z=5.70, P<0.001; Z=6.45, P<0.001).@*Conclusions@#There is difference among different methods and instruments in the test results under the same condition, which call for options in practical work according to need.

Establishment and evaluation of PCR-array for detection of six common pathogens of purulent meningitis in children / 军事医学

Objective To develop a PCR-array method for detecting common purulent meningitis pathogens including Streptococcus pneumoniae,Escherichia coli,Haemophilus influenzae type B,Neisseria meningitidis,S.agalactiae and Listeria monocytogenes in children.Methods The amplification efficiency,limit of detection (LOD) and cross-reactivity were validated with individually real-time PCR using genomic DNA of the six pathogenic bacteria.The sensitivity and specificity of the PCR-array method were evaluated using artificial cerebrospinal fluid(CSF),and the consistency between the PCR-array method and the golden method of CSF culture was evaluated using clinical samples.Results The primers and probes of the pathogens in PCR-array had high specificity,and there was no cross reaction between them.The LOD of the PCR-array method was 10 cfu/ml and very sensitive.The sensitivity and specificity of the PCR-array method could reach 95％ in the evaluation of artificial CSF,and had a good consistency with the clinical gold standard method.Conclusion The PCR-array method with high sensitivity and specificity can simultaneously detect six common pathogens in children with purulent meningitis at 2.5 h,which could provide reference for the diagnosis of purulent meningitis.

Expression and significance of human telomerase reverse transcriptase mRNA in different subtypes of melanoma / 肿瘤研究与临床

Objective To detect the expression of human telomerase reverse transcriptase (hTERT) mRNA in the melanoma, and to analyze the relationship between the expression and subtypes and clinicopathological features of melanoma. Methods Expression of hTERT mRNA was detected by real-time quantitative PCR in 64 cases of melanoma and 30 cases of nevus. SPSS 17.0 software was used to analyze the relationship between hTERT mRNA expression and clinical pathological features of melanoma. Results The relative expression of hTERT mRNA in melanoma tissues was higher than that in nevus tissues [(52.43±5.42) vs (21.38±3.73), t= 4.72, P= 0.000]. The expression of hTERT mRNA in melanoma had no significant correlation with age, gender, ethnicity (all P> 0.05), but had relationship with subtypes, lymph node metastasis, Clark classification (all P 0.05). Conclusions The expression of hTERT mRNA in melanoma is high, especially in mucosal melanoma. hTERT may play an important role in the occurrence and development of melanoma.

Application of Real-time Fluorescent Quantitative PCR in the Identification of Fritillariae Cirrhosae Bulbus / 中国药师

Objective:To investigate the feasibility of real-time fluorescence quantitative PCR in the identification of Fritillariae Cirrhosae Bulbus.Methods:The DNA of samples was extracted by magnetic beads ,the primers were amplified by real-time fluores-cence quantitative PCR , and the Cq value and amplification curve were used to determine the samples .Results:The Cq values for five batches of Fritillariae Cirrhosae Bulbus were lower than 30, and the curve had obvious growth period .No Cq value was shown for Fritil-lariae Ussuriensis Bulbus , Fritillariae Thunbergii Bulbus and Bolbostemmatis Rhizoma with straight line curves .Conclusion:The meth-od is simple,feasible and effective in the identification of Bulbus Fritillariae Cirrhosae with high accuracy and good reproducibility .

Establishing a method for detection of human vitamin D receptor using dual real-time fluorescence quantitative PCR / 天津医药

Objective To establish a dual real-time fluorescence quantitative polymerase chain reaction (dual real-time PCR) assay to detect human vitamin D receptor (VDR) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Methods GAPDH gene was used as the internal control. The specific primers and TaqMan probes were designed by Primer Premier 5.0 software, which were applied to detect the VDR/GAPDH mRNA levels. The obtained PCR products were puri-fied to construct the VDR/GAPDH recombinant plasmid, which was taken as the standard to analyze the sensitivity and re-peatability of the method. Results The amplification products were confirmed as the specific fragment of VDR/GAPDH by DNA sequencing instrument. The results showed that the sensitivity, linear range, the determinate coefficient, the amplifica-tion efficiency, the intra-assay and inter-assay coefficient of variation were 40 copies/μL, 4.00 × 101-4.00 × 105 copies/μL, 0.998, 96.10%, 0.09%-1.21%, 0.17%-0.51%for VDR, and 40 copies/μL, 4.00 × 101-4.00 × 105 copies/μL, 0.999, 85.15%, 0.35%-0.88%, 0.51%-2.46% for GAPDH, respectively. Conclusion These results demonstrate that the dual real-time PCR assay with high sensitivity and specificity can detect the relative expressions of human VDR by single reaction tube, which can effectively shorten the time and reduce the experimental error.

Changes of miRNA-21 in the peripheral blood in patients with chronic heart failure and its clinical significance / 实用医学杂志

Objective To investigate the expression difference of microRNA -21 (miRNA-21) in patients with chronic cardiac function and analyze its clinical significance. Methods Patients with chronic heart failure (trial group,150 cases) and the subjects without chronic heart failure (control group,45 cases) were enrolled. Patients with chronic heart failure were divided into three subgroups according to NYHA: group A (heart function classⅡ,49 cases),group B (classⅢ, 51 cases) and group C (class Ⅳ, 50 cases). miRNA-21 levels were detected by qRT-PCR method. The levels of B type natriuretic peptide urea (BNP),left ventricular end diastole diameter (LVEDD) and left ventricular ejection fraction (LVEF) were determined. Results miRNA-21 expression in patients with heart failure were higher than that of control group (P < 0.01),and miRNA-21 expression in group C was higher than that of group A.Correlation analysis showed that there was a positive correlation between expression of BNP (r = 0.763,P < 0.01), LVEDD (r = 0.691,P<0.01), and the level of miRNA-21 in patients with chronic heart failure.And a negative correlation between LVEF value and the level of miRNA-21 (r = -0.918,P < 0.01). Conclusion miRNA-21 might be a potential marker for diagnosis of heart failure and could be a basis for reference about prognosis evaluation.

Relationship between gene expression of lysine decarboxylase and accumulation of matrine and oxymatrine in Sophora alopecuroides / 中国药学杂志

OBJECTIVE: To study the effect of lysine decarboxylase (LDC) gene on the accumulation of matrine (MA) and oxymatrine (OMA) in cotyledon of Sophora alopecuroides L germinating seeds. METHODS: The S. alopecuroides germinating seeds were stressed by different mass fractions of PEG 6000, and the contents of MA and OMA were determined by high performance liquid chromatography (HPLC) and the expression level of LDC was analyzed by real-time fluorescence quantitative PCR (qPCR) after 72 h treatment. RESULTS: The contents of MA and OMA decreased in the cotyledon under light stress (PEG mass fraction 20%). The analysis of qPCR revealed that the LDC expression level was decreased first, and then increased with the stress rising. The changes of the contents of MA and OMA were parallel with the expression level of LDC especially under light and severe stress. CONCLUSION: There is certain association between the accumulation of MA and OMA and the gene expression quantity of LDC. The results is of significance for illustrating the role of LDC in the biosynthetic pathways of MA and OMA.

Establishment of a TaqMan real-time fluorescence quantitative PCR for detection of murine polyomavirus / 中国比较医学杂志

Objective To establish a rapid,specific and sensitive TaqMan real-time fluorescence quantitative PCR assay for detection of murine polyomavirus ( MPyV) .Methods The specific primers and TaqMan probe were designed based on genome sequence of MPyV.The primers amplified a 69 bp fragment.After optimizing the reaction system and reaction condition, the standard curve was plotted by detecting recombinant plasmid standards.The specificity, sensitivity and reproducibility of this method were evaluated.In addition, samples of lungs, spleens and feces obtained from experimentally infected mice and 86 clinical samples were used to validate the efficacy of this real-time PCR assay.Results The specificity assay showed that this assay could specifically detect MPyV and the sensitivity for MPyV was about 100 copies/well.The coefficients of variation ( CV) of both intra-assay and inter-assay were less than 1.13%.All of the samples from experimentally infected mice were positive for MPyV and 3 out of 86 clinical samples were positive by this TaqMan-PCR detection with a positive rate of 3.5%.Conclusions The real-time fluorescence quantitative TaqMan-PCR assay established in this study has high specificity, sensitivity and stability.It can be used for clinical diagnosis, routine detection and epidemiological investigation of murine polyomavirus infections.

Comparative study of bovine and porcine derived materials in hydrolysate samples by real-time fluorescence quantitative PCR and general PCR / 中国生化药物杂志

Objective To compare real-time fluorescence quantitative PCR with general PCR in detecting bovine and porcine derived materials in hydrolysate samples.Methods DNA were extracted from hydrolysate samples which prepared by different steps by real-time fluorescence quantitative PCR and general PCR.Results DNA of bovine and porcine could be detected by real-time fluorescence quantitative PCR and general PCR in samples prepared in the processes before enzymolysis solution, but not detected in samples from supermatant to the fourth ultrafiltrate.Conclusion Both real-time fluorescence quantitative PCR and general PCR can be applied to detect the fragments in hydrolysate samples.And real-time fluorescence quantitative PCR has the advantage such as rapid,convenient, non-environment-polluted, good repeatability, which improves the quality and efficiency.

Effects of dried whey on the intestinal bacterial community and probiotics in weaned laboratory rabbits / 中国比较医学杂志

Objective To investigate the effects of dried whey on the intestinal bacterial community and probiotics in weaned laboratory rabbits .Methods A single factor design was employed to investigate the effects of dried whey supplemented at levels of 0%, 2%, 5%and 10%, respectively, on 48 weaned (40-day-old) laboratory rabbits.At the day 30, eight rabbits in each group were taken and sacrificed after anesthesia .The total bacterial DNA from the ceacal content of each selected rabbit was drew to analyze the bacterial community and intestinal probiotics ( Bifidobacterium and Lactobacillius) population by PCR-DGGE and real-time fluorescence quantitative PCR, respectively.Results 1) The DGGE parameters of ceacal bacterial community were increased with the increasing dried whey supplemental levels .The number of DGGE band in 2%, 5%and 10%dried whey supplement groups (P0.05).Supplying dried whey has no significant effects on the homogeneity index (P>0.05).2) The population of Bifidobacterium and Lactobacillius in ceacal content had a trend of increase with the rising dried whey supplement levels .Compared with the 0% supplement group , the Lactobacillius population in the 2%, 5% and 10%supplement groups ( P <0.05 ) , the Bifidobacterium population in the 10% supplement group ( P <0.05 ) were significantly increased .Conclusions The results of our study indicate that: 1 ) Supplying dried whey in the feed of laboratory rabbit can effectively increase the diversity of ceacal bacterial community .2) Dried whey may effectively improve the intestinal probiotics population .

Development of real-time fluorescence quantitative RT-PCR assay for β-actin gene of Panax ginseng / 中草药

Objective: To construct a real-time fluorescence quantitative RT-PCR method for the β-actin gene of Panax ginseng. Methods: According to the β-actin gene of other higher plants available in Genbank, A pair of primers weredesigned and the amplified fragment of β-actin gene was linked with pMD20-T vector to construct recombinant plasmids. Then the positive plasmids were diluted and the standard curve was established. The sensitivity, specificity, and repeatability were detected. Results: The results showed that the lowest copy number for detection of β-actin gene with this method was 43.0 copies/μL, and there was a good linear relationship in a wide range from 43 to 4.3 × 107 copies/μL (R2 = 0.995 3). The melting curve showed a single peak with the temperature of (84.51 ± 0.01) ℃. The coefficient of variation (CV) of five different concentration of positive plasmids was 0.58% to 2.79% and 2.61% to 4.41% in intra-assay and inter-assay, respectively. Conclusion: The method established in this paper has the advantage of rapidity, sensitivity, specificity, high throughput, and good repeatability, which provides a methodological basis for the quantitative analysis on the functional genes of P. ginseng when β-actin gene is taken as a reference gene.