scholarly journals Accurate measurement of transgene copy number in crop plants using droplet digital PCR

2017 ◽  
Vol 90 (5) ◽  
pp. 1014-1025 ◽  
Author(s):  
Ray Collier ◽  
Kasturi Dasgupta ◽  
Yan-Ping Xing ◽  
Bryan Tarape Hernandez ◽  
Min Shao ◽  
...  
Keyword(s):  
Copy Number ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Crop Plants ◽  
Transgene Copy Number

scholarly journals DNA isolation protocol effects on nuclear DNA analysis by microarrays, droplet digital PCR, and whole genome sequencing, and on mitochondrial DNA copy number estimation

2017 ◽  
Author(s):  
Elizabeth Nacheva ◽  
Katya Mokretar ◽  
Aynur Soenmez ◽  
Alan M Pittman ◽  
Colin Grace ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Human Brain ◽  
Frontal Cortex ◽  
Genome Sequencing ◽  
Copy Number ◽  
Dna Isolation ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Whole Genome ◽  
Salting Out

AbstractPotential bias introduced during DNA isolation is inadequately explored, although it could have significant impact on downstream analysis. To investigate this in human brain, we isolated DNA from cerebellum and frontal cortex using spin columns under different conditions, and salting-out. We first analysed DNA using array CGH, which revealed a striking wave pattern suggesting primarily GC-rich cerebellar losses, even against matched frontal cortex DNA, with a similar pattern on a SNP array. The aCGH changes varied with the isolation protocol. Droplet digital PCR of two genes also showed protocol-dependent losses. Whole genome sequencing showed GC-dependent variation in coverage with spin column isolation from cerebellum. We also extracted and sequenced DNA from substantia nigra using salting-out and phenol / chloroform. The mtDNA copy number, assessed by reads mapping to the mitochondrial genome, was higher in substantia nigra when using phenol / chloroform. We thus provide evidence for significant method-dependent bias in DNA isolation from human brain, as reported in rat tissues. This may contribute to array “waves”, and could affect copy number determination, particularly if mosaicism is being sought, and sequencing coverage. Variations in isolation protocol may also affect apparent mtDNA abundance.

Abstract P613: Absolute Gene Quantification Of Intrarenal Renin-angiotensin System Components Using Droplet Digital PCR Analysis

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Ryousuke Satou ◽  
Akemi Katsurada ◽  
Kayoko Miyata ◽  
Andrei Derbenev ◽  
Andrea Zsombok
Keyword(s):  
Copy Number ◽  
System Analysis ◽  
Renin Angiotensin System ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Gene Copy ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Copy Numbers ◽  
Intrarenal Ras

The intrarenal renin-angiotensin system (RAS) has been shown to play crucial roles in the development of hypertension and RAS associated kidney injury including diabetic nephropathy. Although some circulating RAS components are filtered into kidneys and contribute to the regulation of intrarenal RAS activity, evaluating expression levels of RAS components in the kidney is important to elucidate the mechanisms underlying intrarenal RAS activation. Digital PCR is a new technique that has been established to quantify absolute target gene levels, which allows for comparisons of different gene levels. Thus, this study was performed to establish profiles of absolute gene copy numbers for intrarenal RAS components in wild-type (WT) rats, WT and streptozotocin (STZ)-induced diabetic mice. Male Sprague-Dawley rats (N=5) and male C57BL/6J mice were used in this study. The mice were subjected to either control (N=5) or STZ (200 mg/kg, N=4) injection. Seven days after STZ injection, copy numbers of renal cortical angiotensinogen (AGT), angiotensin-converting enzyme (ACE), ACE2, angiotensin type 1 receptor a (AT1a), and AT2 mRNA were determined by a droplet digital PCR. Since (pro)renin proteins produced by juxtaglomerular cells are secreted to circulating system, analysis of renin mRNA was excluded from this evaluation. In the renal cortex of WT rats, the copy number of AGT was higher than other measured RAS components (AGT: 719.2±46.6, ACE: 116.0±14.9, ACE2: 183.6±21.5, AT1a: 196.0±25.2 copies in 1 ng total RNA). AT2 levels were lower than other components (0.068±0.01 copies). In WT mice, ACE exhibited the highest copy number in the components (AGT: 447.2±29.0, ACE: 1662.4±61.2, ACE2: 676.8±41.5, AT1a: 867.0±16.8, AT2: 0.049±0.01 copies). Although STZ-induced diabetes did not change ACE2 and AT1a, ACE levels were reduced (765.5±98.1 copies) and AT2 levels were augmented (0.10±0.01 copies) as previously demonstrated. Accordingly, the absolute quantification by digital PCR established precise gene profiles of intrarenal RAS components, which will provide rationales for targeting the each component in future studies. Furthermore, the results indicate that the high sensitive assay accurately quantifies rare target genes including intrarenal AT2.

scholarly journals Comparative analysis of HER2 copy number between plasma and tissue samples in gastric cancer using droplet digital PCR

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Boram Kim ◽  
Soo Kyung Nam ◽  
Soo Hyun Seo ◽  
Kyoung Un Park ◽  
Sang-Hoon Ahn ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Comparative Analysis ◽  
Copy Number ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Tissue Samples

scholarly journals Application of droplet digital PCR for the detection of vector copy number in clinical CAR/TCR T cell products

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Alex Lu ◽  
Hui Liu ◽  
Rongye Shi ◽  
Yihua Cai ◽  
Jinxia Ma ◽  
...  
Keyword(s):  
T Cell ◽  
Copy Number ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Vector Copy Number

scholarly journals Monitoring the HER2 copy number status in circulating tumor DNA by droplet digital PCR in patients with gastric cancer

2016 ◽  
Vol 20 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Katsutoshi Shoda ◽  
Daisuke Ichikawa ◽  
Yuji Fujita ◽  
Kiyoshi Masuda ◽  
Hidekazu Hiramoto ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Copy Number ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Droplet Digital Pcr ◽  
Copy Number Status ◽  
Tumor Dna

scholarly journals Application of Droplet Digital PCR for Estimating Vector Copy Number States in Stem Cell Gene Therapy

2016 ◽  
Vol 27 (5) ◽  
pp. 197-208 ◽  
Author(s):  
Huan-Ting Lin ◽  
Takashi Okumura ◽  
Yukinori Yatsuda ◽  
Satoru Ito ◽  
Hiromitsu Nakauchi ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Stem Cell ◽  
Copy Number ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Vector Copy Number ◽  
Cell Gene ◽  
Stem Cell Gene ◽  
Stem Cell Gene Therapy

scholarly journals Measurement of gene amplifications related to drug resistance in Plasmodium falciparum using droplet digital PCR

2021 ◽  
Author(s):  
Suttipat Srisut ◽  
Kanokon Suwannasin ◽  
Rungirun Sugaram ◽  
Arjen M. Dondorp ◽  
Mallika Imwong
Keyword(s):  
Drug Resistance ◽  
Copy Number ◽  
Gene Copy Number ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Gene Copy ◽  
Antimalarial Drug Resistance ◽  
Quantification Limit ◽  
Field Samples ◽  
The Cost

Abstract Background: Copy number variations (CNVs) of the Plasmodium falciparum multidrug resistance 1 (pfmdr1), P. falciparum pfplasmepsin2 (pfplasmepsin2) and P. falciparum GTP cyclohydrolase 1 (pfgch1) genes are associated with antimalarial drug resistance in P. falciparum malaria. Droplet digital PCR (ddPCR) assays have been developed for accurate assessment of CNVs in several human genes. The aim of the present study was to develop and validate ddPCR assays for detection of the CNVs of P. falciparum genes associated with resistance to antimalarial drugs.Methods: A multiplex ddPCR assay was developed to detect the CNVs in the pfmdr1 and pfplasmepsin2 genes, while a duplex ddPCR assay was developed to detect CNV in the pfgch1 gene. The gene copy number (GCN) quantification limit, as well as the accuracy and precision of the ddPCR assays were determined and compared to conventional quantitative PCR (qPCR). In order to reduce the cost of testing, a multiplex ddPCR assay of two target genes, pfmdr1 and pfplasmepsin2, was validated. In addition, the CNVs of genes of field samples collected from Thailand from 2015 to 2019 (n = 84) were assessed by ddPCR and results were compared to qPCR as the reference assay.Results: There were no significant differences between the GCN results obtained from uniplex andmultiplex ddPCR assays for detection of CNVs in the pfmdr1 and pfplasmepsin2 genes (p = 0.363 and 0.330, respectively). Based on the obtained gene copy number quantification limit, the accuracy and percent relative standard deviation (%RSD) value of the multiplex ddPCR assay were 95% and 5%, respectively, for detection of the CNV of the pfmdr1 gene, and 91% and 5% for detection of the CNV of the pfplasmepsin2 gene. There was no significant difference in gene copy numbers assessed by uniplex or duplex ddPCR assays regarding CNV in the pfgch1 gene (p = 0.276). The accuracy and %RSD value of the duplex ddPCR assay were 95% and 4, respectively, regarding pfgch1 GCN. In the P. falciparum field samples, pfmdr1 and pfplasmepsin2 GCNs were amplified in 15% and 27% of samples from Ubon Ratchathani, Thailand, while pfgch1 GCN was amplified in 50% of samples from Yala, Thailand. There was 100% agreement between the GCN results obtained from the ddPCR and qPCR assays (κ = 1.00). The results suggested that multiplex ddPCR assay is the optional assay for the accurate detection of gene copy number without requiring calibration standards, while the cost and required time are reduced. Based on the results of this study, criteria for GCN detection by ddPCR analysis were generated.Conclusions: The developed ddPCR assays are simple, accurate, precise and cost-effective tools for detection of the CNVs in the pfmdr1, pfplasmepsin2 and pfgch1 genes of P. falciparum. The ddPCR assay is a useful additional tool for the surveillance of antimalarial drug resistance.

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