TWO RAPID EXTRACTION METHODS TO DETECT APPLE SCAR SKIN AND HOP STUNT VIROIDS BY RT-PCR

1998 ◽  
pp. 603-612 ◽  
Author(s):  
H. Osaki ◽  
Y. Ohtsu ◽  
A. Kudo
2020 ◽  
Vol 5 (2) ◽  
pp. 95 ◽  
Author(s):  
Rajashree Chowdhury ◽  
Prakash Ghosh ◽  
Md. Anik Ashfaq Khan ◽  
Faria Hossain ◽  
Khaledul Faisal ◽  
...  

To detect Post-kala-azar leishmaniasis (PKDL) cases, several molecular methods with promising diagnostic efficacy have been developed that involve complicated and expensive DNA extraction methods, thus limiting their application in resource-poor settings. As an alternative, we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay. Skin samples were collected from suspected PKDL cases following their diagnosis through national guidelines. The extracted DNA from three skin biopsy samples using three different extraction methods was subjected to RPA and qPCR. The qPCR and RPA assays exhibited highest sensitivities when reference DNA extraction method using Qiagen (Q) kit was followed. In contrast, the sensitivity of the RPA assay dropped to 76.7% and 63.3%, respectively, when the boil & spin (B&S) and SpeedXtract (SE) rapid extraction methods were performed. Despite this compromised sensitivity, the B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k = 0.831) techniques. As expected, the reference DNA extraction method was found to be superior in terms of diagnostic efficacy. Finally, to apply the rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.


2005 ◽  
Vol 17 (6) ◽  
pp. 574-578 ◽  
Author(s):  
Ming Y. Deng ◽  
He Wang ◽  
Gordon B. Ward ◽  
Tammy R. Beckham ◽  
Thomas S. McKenna

Six RNA extraction methods, i.e., RNAqueous kit, Micro-to-midi total RNA purification system, NucleoSpin RNA II, GenElute mammalian total RNA kit, RNeasy mini kit, and TRIzol LS reagent, were evaluated on blood and 7 tissues from pig infected with classical swine fever virus (CSFV). Each of the 6 extraction methods yielded sufficient RNA for positive results in a real-time reverse transcription–PCR (RT-PCR) for CSFV, and all RNA, except the one extracted from blood by TRIzol LS reagent, yielded positive results in both a conventional RT-PCR for CSFV and a conventional RT-PCR for an endogenous gene encoding β-actin. The RNA extracted from blood by TRIzol LS reagent became positive in both conventional RT-PCR assays when it was diluted to 1:2, 1:4, or up to 1:64 in nuclease-free water. It is concluded that all 6 methods are more or less useful for the detection of CSFV by real-time and conventional RT-PCR in swine blood and tissues. However, some of the 6 reagents offer certain advantages not common to all 6 extraction procedures. For example, RNA extracted by the TRIzol LS reagent constantly had the highest yield; that by the RNAqueous kit had the highest A260/A280 ratio for almost all samples; and that by the NucleoSpin RNA II and the GenElute mammalian total RNA kit was most likely to be free of contaminations with genomic DNA.


2014 ◽  
Vol 53 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Margaret M. Williams ◽  
Thomas H. Taylor ◽  
David M. Warshauer ◽  
Monte D. Martin ◽  
Ann M. Valley ◽  
...  

Real-time PCR (rt-PCR) is an important diagnostic tool for the identification ofBordetella pertussis,Bordetella holmesii, andBordetella parapertussis. Most U.S. public health laboratories (USPHLs) target IS481, present in 218 to 238 copies in theB. pertussisgenome and 32 to 65 copies inB. holmesii. The CDC developed a multitarget PCR assay to differentiateB. pertussis,B. holmesii, andB. parapertussisand provided protocols and training to 19 USPHLs. The 2012 performance exercise (PE) assessed the capability of USPHLs to detect these threeBordetellaspecies in clinical samples. Laboratories were recruited by the Wisconsin State Proficiency Testing program through the Association of Public Health Laboratories, in partnership with the CDC. Spring and fall PE panels contained 12 samples each of viableBordetellaand non-Bordetellaspecies in saline. Fifty and 53 USPHLs participated in the spring and fall PEs, respectively, using a variety of nucleic acid extraction methods, PCR platforms, and assays. Ninety-six percent and 94% of laboratories targeted IS481in spring and fall, respectively, in either singleplex or multiplex assays. In spring and fall, respectively, 72% and 79% of USPHLs differentiatedB. pertussisandB. holmesiiand 68% and 72% identifiedB. parapertussis. IS481cycle threshold (CT) values forB. pertussissamples had coefficients of variation (CV) ranging from 10% to 28%. Of the USPHLs that differentiatedB. pertussisandB. holmesii, sensitivity was 96% and specificity was 95% for the combined panels. The 2012 PE demonstrated increased harmonization of rt-PCRBordetelladiagnostic protocols in USPHLs compared to that of the previous survey.


1998 ◽  
Vol 64 (8) ◽  
pp. 3118-3122 ◽  
Author(s):  
Ousmane Traore ◽  
Charlotte Arnal ◽  
Berengere Mignotte ◽  
Armand Maul ◽  
Henri Laveran ◽  
...  

ABSTRACT Four methods of extraction and three methods of concentration of three enteric viruses from mussels were comparatively evaluated by reverse transcriptase PCR (RT-PCR). Shellfish were experimentally contaminated by immersion in seawater seeded with astrovirus, hepatitis A virus, or poliovirus. Sixty-gram samples of mussel tissues were processed by using borate buffer, glycine solution, saline beef, and saline beef-Freon extraction methods. The viruses were concentrated by precipitation with polyethylene glycol 6000 (PEG 6000) or PEG 8000 or by organic flocculation. RT-PCR was performed with RNA extracts from crude shellfish extracts and concentrates with and without Sephadex LH20 filtration. The glycine solution and borate buffer extraction methods resulted in significantly more RT-PCR-positive samples than the saline beef extraction method. We assessed the efficiency of 20 combinations of extraction and concentration methods. The borate buffer-organic flocculation, borate buffer-PEG 6000, and glycine solution-PEG 6000 combinations gave RT-PCR-positive results for all 27 samples analyzed for the three viruses. Detoxification of the samples by Sephadex LH20 filtration significantly decreased the efficiency of RT-PCR virus detection.


2017 ◽  
Vol 100 (2) ◽  
pp. 492-498 ◽  
Author(s):  
Tigst Demeke ◽  
Jemima Malabanan ◽  
Michelle Holigroski ◽  
Monika Eng

Abstract Seven commercially available DNA extraction kits were compared with a cetyltrimethylammonium bromide (CTAB)method to determine the suitability of the extracted DNA for RainDrop digital PCR (dPCR) and real-time PCR (RT-PCR) quantification of OXY235 canola, FP967 flax, and DP305423 soybean (spiked at the 0.1% level). For the kits, the highest amount of DNA extracted from a 0.2 g sample was obtained using OmniPrep for Plant for flax andDNeasy mericon Food for canola and soybean. For canola, DNA extracted with the Fast ID Genomic DNA Extraction Kit, FastDNA Spin Kit, GM Quicker 2, NucleoSpin Food, and DNeasy mericon Food was suitable for dPCR and RT-PCR. For flax, DNA extracted with Fast ID, FastDNA Spin Kit, OmniPrep for Plant, and NucleoSpin Food was suitable for RT-PCR. However, only Fast ID yielded DNA suitable for dPCR. For soybean, DNA extracted with five and six of the seven DNA extraction kits was suitable for dPCR and RT-PCR, respectively. Overall, Fast ID provided reliable results regardless of species or analysis method used. Canola, flax, and soybean DNA extracted with the CTAB method and then purified were suitable for both dPCR and RT-PCR. This is the first report showing the effect of different DNA extraction methods on the absolute quantification of genetically engineered traits using dPCR.


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