• Title/Summary/Keyword: Quantitative real time RT-PCR

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Detection of HER2 Status in Breast Cancer: Comparison of Current Methods with MLPA and Real-time RT-PCR

  • Pazhoomand, Reza;Keyhan, Elahe;Banan, Mehdi;Najmabad, Hossein;Karimlou, Masoud;Khodadad, Faranak;Iraniparast, Alireza;Feiz, Farnaz;Majidzadeh, Keivan;Bahman, Ideh;Moghadam, Fatemeh Aghakhani;Sobhani, Atoosa Madadkar;Abedin, Seyedeh Sedigheh;Muhammadnejad, Ahad;Behjat, Farkhondeh
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7621-7628
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    • 2013
  • Human epidermal growth factor receptor (HER) status is an important prognostic factor in breast cancer. There is no globally accepted method for determining its status, and which method is most precise is still a matter of debate. We here analyzed HER2 mRNA expression by quantitative reverse transcription-PCR (qRT-PCR) and HER2 DNA amplification using multiplex ligation-dependent probe amplification (MLPA). In parallel, we performed a routine evaluation of HER2 protein by immunohistochemistry (IHC). To assess the accuracy of the RT-PCR and MLPA techniques, a combination of IHC and fluorescence in situ hybridization (FISH) was used, substituting FISH when the results of IHC were ambiguous (2+) and for those IHC results that disagreed with MLPA and qRT-PCR, this approach being termed IHC-FISH. The IHC results for four samples were not compatible with the MLPA and qRT-PCR results; the MLPA and qRT-PCR results for these samples were confirmed by FISH. The correlations between IHC-FISH and qRT-PCR or MLPA were 0.945 and 0.973, respectively. The ASCO/CAP guideline IHC/FISH correlation with MLPA was (0.827) and with RT-PCR was (0.854). The correlations between the IHC results (0, 1+ as negative, and 3+ as positive) and qRT-PCR and MLPA techniques were 0.743 and 0.831, respectively. Given the shortcomings of IHC analysis and greater correlations between MLPA, qRT-PCR, and FISH methods than IHC analysis alone with each of these three methods, we propose that MLPA and real-time PCR are good alternatives to IHC. However a suitable cut-off point for qRTPCR is a prerequisite for determining the exact status of HER2.

Tissue-specific gene expression analysis of silkworm (Bombyx mori) by quantitative real-time RT-PCR

  • Park, Seung-Won;Kang, Seok-Woo;Goo, Tae-Won;Kim, Seong-Ryul;Lee, Gwang-Gill;Paik, Soon-Young
    • BMB Reports
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    • v.43 no.7
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    • pp.480-484
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    • 2010
  • The Bombyx mori Microarray Database (BmMDB; http://silkworm.swu.edu.cn/microarray) provides information for tissue-specific gene expression by using the whole-genome oligonucleotide microarray in the silkworm. We analyzed the tissue-specific expression patterns in the silk gland, fat body, and midgut five days of fifth instar larvae during the development of B. mori. To verify the tissue-specific expression, analysis was conducted using quantitative Real-time RT-PCR and the highly expressed endogenous Actin RNA as an intrinsic reference. Finally, we confirmed five genes, (sw15872, sw00692, sw20990, sw05300,and sw2250), out of 18 candidates expressed in two different tissues, which was consistent with the data published by Dr. Xiang's group, thereby supporting the BmMDB. Further studies for promoter regions of candidate genes can be applied in creating transgenic silkworms as biomedical insects for use in producing biomaterials, and to serve as well-characterized models for understanding the mechanism for the genetic regulation of tissue-specific development.

Selection of Reliable Reference Genes for Real-time qRT-PCR Analysis of Zi Geese (Anser anser domestica) Gene Expression

  • Ji, Hong;Wang, Jianfa;Liu, Juxiong;Guo, Jingru;Wang, Zhongwei;Zhang, Xu;Guo, Li;Yang, Huanmin
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.3
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    • pp.423-432
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    • 2013
  • Zi geese (Anser anser domestica) belong to the white geese and are excellent layers with a superior feed-to-egg conversion ratio. Quantitative gene expression analysis, such as Real-time qRT-PCR, will provide a good understanding of ovarian function during egg-laying and consequently improve egg production. However, we still don't know what reference genes in geese, which show stable expression, should be used for such quantitative analysis. In order to reveal such reference genes, the stability of seven genes were tested in five tissues of Zi geese. Methodology/Principal Findings: The relative transcription levels of genes encoding hypoxanthine guanine phosphoribosyl transferase 1 (HPRT1), ${\beta}$-actin (ACTB), ${\beta}$-tubulin (TUB), glyceraldehyde-3-phosphate-dehydrogenase (GADPH), succinate dehydrogenase flavoprotein (SDH), 28S rRNA (28S) and 18S rRNA (18S) have been quantified in heart, liver, kidney, muscle and ovary in Zi geese respectively at different developmental stages (1 d, 2, 4, 6 and 8 months). The expression stability of these genes was analyzed using geNorm, NormFinder and BestKeeper software. Conclusions: The expression of 28S in heart, GAPDH in liver and ovary, ACTB in kidney and HPRT1 in muscle are the most stable genes as identified by the three different analysis methods. Thus, these genes are recommended for use as candidate reference genes to compare mRNA transcription in various developmental stages of geese.

pH-Dependence of RNA Extraction for Norovirus by TRIzol Method (TRIzol을 이용한 노로바이러스 RNA 추출의 pH 의존성)

  • Jhon, Deok-Young
    • Journal of Food Hygiene and Safety
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    • v.33 no.1
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    • pp.71-76
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    • 2018
  • Norovirus is a leading cause of sporadic pathogenic non-bacterial gastroenteritis worldwide. For the detection of norovirus, reverse transcription real-time PCR (RT qPCR) has quickly become a major tool due to its sensitivity and specificity. However, accurate viral RNA extraction methods are essential for RT qPCR analysis. TRIzol reagents are used to extract RNA from biological materials and are therefore widely used for norovirus RNA extraction. In this study, the yield of viral RNA extraction using TRIzol from genogroup II (GII) among the human norovirus genogroup I (GI) and GII, and murine norovirus (GV) depended on the pH of the virus sample solution. The yield of RNA extraction was higher at the alkaline pH than in the acidic region compared with the Ct (threshold cycle) value of the real-time PCR. From the results of this study, it was found that the pH condition is very important for the quantitative analysis of norovirus by extracting GII RNA using TRIzol.

Effect of Ferulic Acid Isolated from Cnidium Officinale on the Synthesis of Hyaluronic Acid (천궁으로부터 분리된 ferulic acid의 히알루론산 생성에 미치는 효과)

  • Song, Hye Jin;Jin, Mu Hyun;Lee, Sang Hwa
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.4
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    • pp.281-288
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    • 2013
  • Hyaluronic acid (HA) is one of the major extracellular matrix components in skin. The HA content is reported to decline with age, which may contribute to decrease in skin moisture, wrinkle formation and the decrease in elasticity of the skin. Among the family of HA synthase genes (HAS-1, 2, 3) identified so far, HAS-2 plays crucial roles in the regulation of HA synthesis in human skin fibroblasts. In this study, we elucidated the effects of ferulic acid isolated from Cnidium officinale on HA production. Semi-quantitative RT-PCR and quantitative real-time PCR showed that ferulic acid increased mRNA level of HAS-2 gene and ELISA assay also revealed that ferulic acid increased HA production in human skin fibroblasts. Our study suggests that ferulic acid might prevent age-dependent skin deteriorations such as wrinkles, dryness and elasticity decrease, all of which could be ascribed to the reduction of the HA content in human skin.

Study of Bacteria Associated with Dental Caries Using a 3 Tone Disclosing Agent (세가지 색상차이를 보이는 착색제를 이용한 치아 우식 관련 균에 관한 연구)

  • Lee, Jeongeun;Park, Howon;Lee, Juhyun;Seo, Hyunwoo;Lee, Siyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.1
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    • pp.32-40
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    • 2018
  • The aim of this study was to determine the efficacy of a 3 tone plaque disclosing gel in assessing the risk of caries related to the population of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus spp. quantified using a quantitative real-time polymerase chain reaction (qRT-PCR). 15 healthy children of ages 9 - 12 years were randomly examined. The 3 tone plaque disclosing gel was applied on teeth surfaces, which changed the color to pink or red, blue or purple and light blue. Plaque was divided into 3 groups based on staining. Genomic DNA from each sample was subjected to a qRT-PCR assay for quantitative detection of target bacteria. The Kruskal-Wallis test was conducted for correlation between the color of plaque and the number of bacterial species. The levels of S. mutans, S. sobrinus, and Lactobacillus spp. were significantly different in the plaque samples of the 3 groups (p < 0.05). The proportion of S. sobrinus to S. mutans showed correlation to the color of plaque. The different color-dyed plaque was related to the number of acidogenic bacteria. The 3 tone plaque disclosing gel could be used as one of the indicators to assess the clinical risk of caries associated with the population of S. mutans, S. sobrinus, and Lactobacillus spp.

Development of a multiplex qRT-PCR assay for detection of African swine fever virus, classical swine fever virus and porcine reproductive and respiratory syndrome virus

  • Chen, Yating;Shi, Kaichuang;Liu, Huixin;Yin, Yanwen;Zhao, Jing;Long, Feng;Lu, Wenjun;Si, Hongbin
    • Journal of Veterinary Science
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    • v.22 no.6
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    • pp.87.1-87.12
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    • 2021
  • Background: African swine fever virus (ASFV), classical swine fever virus (CSFV), and porcine reproductive and respiratory syndrome virus (PRRSV) are still prevalent in many regions of China. Co-infections make it difficult to distinguish their clinical symptoms and pathological changes. Therefore, a rapid and specific method is needed for the differential detection of these pathogens. Objectives: The aim of this study was to develop a multiplex real-time quantitative reverse transcription polymerase chain reaction (multiplex qRT-PCR) for the simultaneous differential detection of ASFV, CSFV, and PRRSV. Methods: Three pairs of primers and TaqMan probes targeting the ASFV p72 gene, CSFV 5' untranslated region, and PRRSV ORF7 gene were designed. After optimizing the reaction conditions, including the annealing temperature, primer concentration, and probe concentration, multiplex qRT-PCR for simultaneous and differential detection of ASFV, CSFV, and PRRSV was developed. Subsequently, 1,143 clinical samples were detected to verify the practicality of the assay. Results: The multiplex qRT-PCR assay could specifically and simultaneously detect the ASFV, CSFV, and PRRSV with a detection limit of 1.78 × 100 copies for the ASFV, CSFV, and PRRSV, but could not amplify the other major porcine viruses, such as pseudorabies virus, porcine circovirus type 1 (PCV1), PCV2, PCV3, foot-and-mouth disease virus, porcine parvovirus, atypical porcine pestivirus, and Senecavirus A. The assay had good repeatability with coefficients of variation of intra- and inter-assay of less than 1.2%. Finally, the assay was used to detect 1,143 clinical samples to evaluate its practicality in the field. The positive rates of ASFV, CSFV, and PRRSV were 25.63%, 9.36%, and 17.50%, respectively. The co-infection rates of ASFV+CSFV, ASFV+PRRSV, CSFV+PRRSV, and ASFV+CSFV+PRRSV were 2.45%, 2.36%, 1.57%, and 0.17%, respectively. Conclusions: The multiplex qRT-PCR developed in this study could provide a rapid, sensitive, specific diagnostic tool for the simultaneous and differential detection of ASFV, CSFV, and PRRSV.

Analysis of Hemocyte-specific Gene Expression from Bombyx mori

  • Park, Seung-Won;Goo, Tae-Won;Kim, Seong-Ryul;Kang, Seok-Woo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.23 no.1
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    • pp.137-141
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    • 2011
  • A previous data was provided information for tissuespecific expression genes by means of whole-genome oligonucleotide microarray in the silkworm. We analyzed the tissue-specific expression patterns in the hemocyte tissue on 5 days of 5th instar larvae during the development of $B.$ $mori$. Total 5 candidates pick out from the $Bombyx$ $mori$ Microarray Database (BmMDB; http://silkworm.swu.edu.cn/microarray). To verify the hemocyte-specific expression, we analyzed by semi-quantitative and real-time quantitative RT-PCR using the highly expressed endogenous $Actin$ RNA as an intrinsic reference. In this study, we confirmed that one gene-sw17255- out of 5 candidates expressed in the hemocyte tissue, which was consistent with the previous data. Circulating hemocytes in the body fluid of the $B.$ $mori$ are most powerful target organ for producing biomaterials. We need further studies to find hemocyte-specific promoter region from sw17255 gene. Finally, this result can be applied in creating transgenic silkworms as a biomedical insect.

Expression of vascular endothelial growth factor in oral squamous cell carcinoma

  • Kim, Seok-Kon;Park, Seung-Goo;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.41 no.1
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    • pp.11-18
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    • 2015
  • Objectives: The goal of this study was to determine the correlation of clinicopathological factors and the up-regulation of vascular endothelial growth factor (VEGF) expression in oral squamous cell carcinoma. Materials and Methods: Immunohistochemical staining of VEGF and quantitative real-time polymerase chain reaction (RT-PCR) of VEGF mRNA were performed in 20 specimens from 20 patients with oral squamous cell carcinoma and another 20 specimens from 20 patients with carcinoma in situ as a controlled group. Results: The results were as follows: 1) In immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, high-level staining of VEGF was observed. Significant correlation was observed between immunohistochemical VEGF expression and histologic differentiation, tumor size of specimens (Pearson correlation analysis, significance r>0.6, P<0.05). 2) In VEGF quantitative RT-PCR analysis, progressive cancer showed more VEGF expression than carcinoma in situ. Paired-samples analysis determined the difference of VEGF mRNA expression level between cancer tissue and carcinoma in situ tissue, between T1 and T2-4 (Student's t-test, P<0.05). Conclusion: These findings suggest that up-regulation of VEGF may play a role in the angiogenesis and progression of oral squamous cell carcinoma.

Establishment of Quantitative Analysis Method for Genetically Modified Maize Using a Reference Plasmid and Novel Primers

  • Moon, Gi-Seong;Shin, Weon-Sun
    • Preventive Nutrition and Food Science
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    • v.17 no.4
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    • pp.274-279
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    • 2012
  • For the quantitative analysis of genetically modified (GM) maize in processed foods, primer sets and probes based on the 35S promoter (p35S), nopaline synthase terminator (tNOS), p35S-hsp70 intron, and zSSIIb gene encoding starch synthase II for intrinsic control were designed. Polymerase chain reaction (PCR) products (80~101 bp) were specifically amplified and the primer sets targeting the smaller regions (80 or 81 bp) were more sensitive than those targeting the larger regions (94 or 101 bp). Particularly, the primer set 35F1-R1 for p35S targeting 81 bp of sequence was even more sensitive than that targeting 101 bp of sequence by a 3-log scale. The target DNA fragments were also specifically amplified from all GM labeled food samples except for one item we tested when 35F1-R1 primer set was applied. A reference plasmid pGMmaize (3 kb) including the smaller PCR products for p35S, tNOS, p35S-hsp70 intron, and the zSSIIb gene was constructed for real-time PCR (RT-PCR). The linearity of standard curves was confirmed by using diluents ranging from $2{\times}10^1{\sim}10^5$ copies of pGMmaize and the $R^2$ values ranged from 0.999~1.000. In the RT-PCR, the detection limit using the novel primer/probe sets was 5 pg of genomic DNA from MON810 line indicating that the primer sets targeting the smaller regions (80 or 81 bp) could be used for highly sensitive detection of foreign DNA fragments from GM maize in processed foods.