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Find video protocols related to scientific articles indexed in Pubmed.
Long-term thiol monitoring in living cells using bioorthogonal chemistry.
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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Intracellular thiols play vital roles in living systems, and their in situ monitoring is of great importance. Here, we report on a bioorthogonal chemistry based fluorescent probe, which is capable of monitoring intracellular thiols in living cells for up to 36 hours with an obvious blue-to-green fluorescence change.
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Rapid synthesis of isoquinolinones by intramolecular coupling of amides and ketones.
Org. Biomol. Chem.
PUBLISHED: 11-20-2014
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Amides and ketones were intramolecularly coupled in the presence of KOt-Bu/DMF. The reaction provided good yields of a variety of isoquinolinones. A reaction mechanism of radical addition and subsequent E2-elimination is proposed.
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A pH-responsive prodrug for real-time drug release monitoring and targeted cancer therapy.
Chem. Commun. (Camb.)
PUBLISHED: 08-23-2014
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A novel cancer targeting and pH-responsive prodrug was successfully designed and synthesized. This M-prodrug was demonstrated to have real-time drug release monitoring capability based on the concept of contact-mediated quenching between doxorubicin and a coumarin derivative.
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Stepwise-acid-active multifunctional mesoporous silica nanoparticles for tumor-specific nucleus-targeted drug delivery.
ACS Appl Mater Interfaces
PUBLISHED: 08-18-2014
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In this paper, a novel stepwise-acid-active multifunctional mesoporous silica nanoparticle (MSN-(SA)TAT&(DMA)K11) was developed as a drug carrier. The MSN-(SA)TAT&(DMA)K11 is able to reverse its surface charge from negative to positive in the mildly acidic tumor extracellular environment. Then, the fast endo/lysosomal escape and subsequent nucleus targeting as well as intranuclear drug release can be realized after cellular internalization. Because of the difference in acidity between the tumor extracellular environment and that of endo/lysosomes, this multifunctional MSN-(SA)TAT&(DMA)K11 exhibits a stepwise-acid-active drug delivery with a tumor-specific nucleus-targeted property.
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Aberrant PTPRO methylation in tumor tissues as a potential biomarker that predicts clinical outcomes in breast cancer patients.
BMC Genet.
PUBLISHED: 06-04-2014
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Aberrant hypermethylation of gene promoter regions is a primary mechanism by which tumor suppressor genes become inactivated in breast cancer. Epigenetic inactivation of the protein tyrosine phosphatase receptor-type O gene (PTPRO) has been described in several types of cancer.
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Skewer: a fast and accurate adapter trimmer for next-generation sequencing paired-end reads.
BMC Bioinformatics
PUBLISHED: 03-23-2014
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Adapter trimming is a prerequisite step for analyzing next-generation sequencing (NGS) data when the reads are longer than the target DNA/RNA fragments. Although typically used in small RNA sequencing, adapter trimming is also used widely in other applications, such as genome DNA sequencing and transcriptome RNA/cDNA sequencing, where fragments shorter than a read are sometimes obtained because of the limitations of NGS protocols. For the newly emerged Nextera long mate-pair (LMP) protocol, junction adapters are located in the middle of all properly constructed fragments; hence, adapter trimming is essential to gain the correct paired reads. However, our investigations have shown that few adapter trimming tools meet both efficiency and accuracy requirements simultaneously. The performances of these tools can be even worse for paired-end and/or mate-pair sequencing.
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DLC1-dependent parathyroid hormone-like hormone inhibition suppresses breast cancer bone metastasis.
J. Clin. Invest.
PUBLISHED: 03-03-2014
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Bone metastasis is a frequent complication of breast cancer that is often accelerated by TGF-? signaling; however, little is known about how the TGF-? pathway is regulated during bone metastasis. Here we report that deleted in liver cancer 1 (DLC1) is an important regulator of TGF-? responses and osteolytic metastasis of breast cancer cells. In murine models, breast cancer cells lacking DLC1 expression exhibited enhanced capabilities of bone metastasis. Knockdown of DLC1 in cancer cells promoted bone metastasis, leading to manifested osteolysis and accelerated death in mice, while DLC1 overexpression suppressed bone metastasis. Activation of Rho-ROCK signaling in the absence of DLC1 mediated SMAD3 linker region phosphorylation and TGF-?-induced expression of parathyroid hormone-like hormone (PTHLH), leading to osteoclast maturation for osteolytic colonization. Furthermore, pharmacological inhibition of Rho-ROCK effectively reduced PTHLH production and breast cancer bone metastasis in vitro and in vivo. Evaluation of clinical breast tumor samples revealed that reduced DLC1 expression was linked to elevated PTHLH expression and organ-specific metastasis to bone. Overall, our findings define a stroma-dependent paradigm of Rho signaling in cancer and implicate Rho-TGF-? crosstalk in osteolytic bone metastasis.
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No association between XRCC1 gene Arg194Trp polymorphism and risk of lung cancer: evidence based on an updated cumulative meta-analysis.
Tumour Biol.
PUBLISHED: 02-10-2014
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X-ray repair cross-complementing group 1 (XRCC1) gene Arg194Trp polymorphism has been reported to be associated with risk of lung cancer in many published studies. Nevertheless, the research results were inconclusive and conflicting. To reach conclusive results, several meta-analysis studies were conducted by combining results from literature reports through pooling analysis. However, these previous meta-analysis studies were still not consistent. Hence, we used an updated and cumulative meta-analysis to get a more comprehensive and precise result from 25 case-control studies searching through the PubMed database up to September 1, 2013. The meta-analysis was carried out by the Comprehensive Meta-Analysis software and the odds ratio (OR) with 95 % confidence interval (CI) was used to estimate the pooled effect. The result involving 8,876 lung cancer patients and 11,210 controls revealed that XRCC1 Arg194Trp polymorphism was not associated with lung cancer risk [(OR=0.97, 95 %CI=0.92-1.03) for Trp vs. Arg; (OR=0.92, 95 % CI=0.85-0.98) for ArgTrp vs. ArgArg; (OR=1.07, 95 % CI=0.92-1.23) for TrpTrp vs. ArgArg; (OR=0.93, 95 % CI=0.87-1.00) for (TrpTrp?+?ArgTrp) vs. ArgArg; and (OR=1.08, 95 % CI=0.94-1.25) for TrpTrp vs. (ArgTrp?+?ArgArg)]. The cumulative meta-analysis showed that the results maintained the same, while the ORs with 95 % CI were more stable with the accumulation of case-control studies. The sensitivity and subgroups analyses showed that the results were robust and not affected by any single study with no publication bias. Relevant studies might not be needed for supporting these results.
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[Effects of herbivorous insect stress on the growth and yield-related traits of insect-resistant transgenic rice].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 12-31-2013
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A field experiment was conducted to test the effects of high and low herbivorous insect stresses on the growth, development and yield-related traits of insect-resistant transgenic rice. Three Bt transgenic rice Bt63, R1 and R2 were selected as the test materials, and non-transgenic rice Shanyou63 was taken as the control. The differences in the vegetative growth, seed-setting, and stem borer resistance between transgenic and non-transgenic rice were compared. Under herbivorous insect stress, the transgenic rice fully displayed the stem borer-resistance of exogenous gene. Under the high stress, the stem borer-damaged degree of the three transgenic rice lines was much lower than that of the control. The plant height, tillers per plant, aboveground fresh mass, panicle length, panicle fresh mass, productive panicles per plant, filled grains per plant, grain mass per plant, seed setting rate, and 1000-grain mass of the three transgenic rice lines excelled the control, but had no significant differences except plant height, tillers per plant, and panicle length. Therefore, introducing exogenous Bt gene into rice had no negative effect on rice seed-setting, and high herbivorous insect stress had less impacts on transgenic rice yield.
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A coumarin derivative as a fluorogenic glycoproteomic probe for biological imaging.
Chem. Commun. (Camb.)
PUBLISHED: 11-26-2013
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Fluorescence imaging in living cells is typically carried out using a functionalized fluorescent dye. But it often causes strong background noise under many conditions where washing is not applicable. Here, we report on a coumarin based fluorogenic probe, which can be used as a bioorthogonal-labeling tool for glycoproteins. The results indicated that the probe was able to image glycoproteins in living cells and it may also be suitable for intracellular imaging.
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Synthesis and antitumor activity of tetrandrine derivatives.
J Asian Nat Prod Res
PUBLISHED: 08-14-2013
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Tetrandrine possesses antitumor activity, however, only a few studies on its structure modification were reported. To improve the antitumor activity of tetrandrine, 20 new tetrandrine derivatives were designed and synthesized by Sonogashira and Suzuki reactions. Their antitumor activities were evaluated against three tumor cell lines including A549, HepG2, and BGC-823 by methyl thiazolyl tetrazolium assay with taxol as a positive control. The results showed that compounds 2c and 2g were highly potent against BGC-823 cell line, and compounds 1i and 1k showed particular activity against HepG2 cells. These results demonstrated that compounds 1i, 1k, 2c, and 2g were promising leads for further investigation.
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One-pot construction of functional mesoporous silica nanoparticles for the tumor-acidity-activated synergistic chemotherapy of glioblastoma.
ACS Appl Mater Interfaces
PUBLISHED: 08-02-2013
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Mesoporous silica nanoparticles (MSNs) have proved to be an effective carrier for controlled drug release and can be functionalized easily for use as stimuli-responsive vehicles. Here, a novel intelligent drug-delivery system (DDS), camptothecin (CPT)-loaded and doxorubicin (DOX)-conjugated MSN (CPT@MSN-hyd-DOX), is reported via a facile one-pot preparation for use in synergistic chemotherapy of glioblastoma. DOX was conjugated to MSNs via acid-labile hydrazone bonds, and CPT was loaded in the pores of the MSNs. At pH 6.5 (analogous to the pH in tumor tissues), a fast DOX release was observed that was attributed to the hydrolysis of the hydrazone bonds. In addition, a further burst release of DOX was found at pH 5.0 (analogous to the pH in lyso/endosomes of tumor cells), leading to a strong synergistic effect. In all, CPT and DOX could be delivered simultaneously into tumor cells, and this intelligent DDS has great potential for tumor-trigged drug release for use in the synergistic chemotherapy of tumors.
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Theranostic GO-Based Nanohybrid for Tumor Induced Imaging and Potential Combinational Tumor Therapy.
Small
PUBLISHED: 05-24-2013
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Graphene oxide (GO)-based theranostic nanohybrid is designed for tumor induced imaging and potential combinational tumor therapy. The anti-tumor drug, Doxorubicin (DOX) is chemically conjugated to the poly(ethylenimine)-co-poly(ethylene glycol) (PEI-PEG) grafted GO via a MMP2-cleavable PLGLAG peptide linkage. The therapeutic efficacy of DOX is chemically locked and its intrinsic fluorescence is quenched by GO under normal physiological condition. Once stimulated by the MMP2 enzyme over-expressed in tumor tissues, the resulting peptide cleavage permits the unloading of DOX for tumor therapy and concurrent fluorescence recovery of DOX for in situ tumor cell imaging. Attractively, this PEI-bearing nanohybrid can mediate efficient DNA transfection and shows great potential for combinational drug/gene therapy. This tumor induced imaging and potential combinational therapy will open a window for tumor treatment by offering a unique theranostic approach through merging the diagnostic capability and pathology-responsive therapeutic function.
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[Determination of cetirizine dihydrochloride by anti-fluorescence quenching on rhodamine B-sodium tetraphenylborate system].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-19-2011
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The sodium tetraphenylboron has the fluorescence quenching effect on rhodamine B, making the fluorescence signal intensity weaken or even disappear. But cetirizine dihydrochloride has the anti-quenching effect on rhodamine B--the fluorescence signal is enhanced, and there was a linear relationship between the fluorescence signal enhancement degree and drug concentration. In the present paper, 491 and 610 nm were chosen as the excitation and emission wavelength for measurement of the fluorescence intensity difference deltaF = F1 - F0 of blank solution and test solution, and according to positive correlation between the value of deltaF and cetirizine hydrochloride concentration of test solution, a new method of anti-fluorescence quenching for the determination of cetirizine hydrochloride was established. The linear regression equation was deltaF = 0.727 5m - 2.357, correlation coefficient was 0.997 2, linear range was 3.50-129.3 mg x L(-1), the detection limit was 1.05 mg x L(-1) and RSD was 1.2%. The cetirizine hydrochloride tablets and cetirizine hydrochloride capsules from different manufacturers were determined by this method, the measured values were basically in line with the labeled amount of drugs, and the recovery rate was between 92% and 106%.
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Development of an improved method to extract pesticide residues in foods using acetonitrile with magnesium sulfate and chloroform.
J Chromatogr A
PUBLISHED: 01-10-2011
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A multiresidue method was developed based on extraction of 10 g sample with 10 mL acetonitrile and subsequent liquid-liquid partitioning formed by adding 4 g MgSO? plus 1 mL chloroform. During the partitioning process, the extraction recoveries of polar analytes were found to be essentially determined by the acetonitrile content in the aqueous phase. The use of MgSO? gave the least acetonitrile left in the aqueous phase (lower than 5%) and thus promoting complete partitioning of analytes into the organic phase. At the same time, removal of water from the acetonitrile phase was achieved by adding only a small amount of chloroform with no influence on the acetonitrile content in the aqueous phase, thus leading to decreasing the co-extraction of polar matrix components. The most complete mutual separation of acetonitrile and water was achieved by the joint use of MgSO? and chloroform and thus the optimal extraction recovery and analytical selectivity were obtained simultaneously. The new method, with higher recoveries of polar analytes, better analytical selectivity and simpler manipulation, is a claimed improvement to the original QuEChERS method. The proposed method was finally validated by the determination of 20 pesticides in a mixed food matrix by using liquid chromatography tandem mass spectrum (LC-MS/MS). Acceptable linearity, sensitivity, recovery, precision and selectivity results were obtained.
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[Effects of hydrodynamics-mediated RNAi on Mfn2 expression, blood sugar and fat levels in mice].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 11-10-2010
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To investigate the effects of hydrodynamics-mediated RNAi for Mfn2 gene expression in liver and the levels of blood sugar and fat in mice.
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Common polymorphisms in ITGA2, PON1 and THBS2 are associated with coronary atherosclerosis in a candidate gene association study of the Chinese Han population.
J. Hum. Genet.
PUBLISHED: 05-20-2010
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Coronary atherosclerosis is a complex and progressive condition that involves many biological pathways, including the oxidative stress and inflammatory response pathways. To investigate the association between common genetic variation within these two pathways and coronary atherosclerosis, we performed a comprehensive two-stage candidate gene association study in a Chinese Han population. In stage I, 936 tag single-nucleotide polymorphisms (SNPs) within 116 candidate genes were genotyped in 293 coronary atherosclerosis cases and 293 age- and gender-matched healthy controls. In stage II, 51 SNPs from stage I were selected and further genotyped in an additional 1030 cases and 764 controls. In allele- and genotype-based association tests of stage II and a meta-analysis across the two stages, we identified three SNPs within three genes significantly associated with the disease, namely rs3212556 in ITGA2 (P(CMH)=9.20 x 10(-5)), rs854563 in PON1 (P(CMH)=1.92 x 10(-4)) and rs9283851 in THBS2 (P(CMH)=3.00 x 10(-3)). Haplotype analysis provided further supporting evidence for the association of rs3212556 (P(global)<10(-4)) and rs854563 (P(global)<10(-4)). Our study has identified three SNPs within ITGA2, PON1 and THBS2 that are associated with coronary atherosclerosis.
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Determination of human urinary kanamycin in one step using urea-enhanced surface plasmon resonance light-scattering of gold nanoparticles.
Anal Bioanal Chem
PUBLISHED: 06-24-2009
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The purpose of this study was to establish a simple, sensitive analytical method for kanamycin (KANA) in human urine. Enhancement of the plasmon resonance light-scattering (PRLS) of gold nanoparticles (AuNPs) by KANA provided the basis for this analytical method. At pH 6.7, KANA induced AuNPs aggregation with enhanced PRLS. The PRLS of the AuNPs-KANA system was further enhanced by addition of urea. The linear range and detection limit for KANA were from 20-800 nmol L(-1) and 2 nmol L(-1), respectively. Potential interfering substances present in urine had a negligible effect on the determination, thus preliminary sample separations were not necessary. Recovery of KANA from spiked human urine was 94-104%. This simple, sensitive method, using urea to enhance the PRLS of the AuNPs-KANA system, may provide a new approach for determination of compounds rich in OH groups.
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Induction of ERBB2 nuclear transport after radiation in breast cancer cells.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 06-10-2009
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The ERBB2 nuclear transport in breast cancer cell lines after radiation and its possible role in radiation tolerance were observed. Confocal microscopy and Western blotting were applied to detect the nuclear ERBB2 expression after radiation in breast carcinomas cells. And the effects of Herceptin, AG825 and Cisplatin on the expression of nuclear ERBB2 were investigated. Survival fractions were also observed. After radiation, compared with control group, confocal microscopy and Western blot revealed that the expression of nuclear ERBB2 was increased in breast cancer cells time-dependently. Herceptin, and AG825 could significantly inhibit the radiation-induced nuclear ERBB2 expression, and decrease survival fractions. Cisplatin also induced the nuclear ERBB2 expression in breast cancer cells with high ERBB2 expression. It was concluded that radiation could induce ERBB2 nuclear transport, and nuclear ERBB2 may correlate with radiation resistance in breast cancer cells with high ERBB2 expression.
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Imaging biocatalytic activity of enzyme-polymer spots by means of combined scanning electrochemical microscopy/electrogenerated chemiluminescence.
Anal. Chem.
PUBLISHED: 05-16-2009
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The purpose of this study was to develop a scanning electrochemical microscopy (SECM) and scanning electrogenerated chemiluminescence (SECL) setup to visualize the localized enzymatic activity using glucose oxidase as a model. Combination of SECM and electrogenerated chemiluminescence (ECL) was made possible by integrating a photomultiplier tube (PMT) within a SECM setup which is mounted on top of an inverted microscope. An enzyme-polymer spot formed on a glass slide and placed on top of the entrance window of the PMT was used as a model sample to evaluate the potential of the combined SECM/ECL setup. Hydrogen peroxide, which was locally generated by the glucose oxidase (GOx)-catalyzed reaction, reacted with oxidized luminol which was simultaneously electrochemically generated at the positioned SECM electrode tip. By using the phase-sensitive lock-in amplifier, the potential applied to the SECM tip was sinusoidally swept to invoke an associated oscillation of the ECL. Thus, sensitivity of SECL could be substantially enhanced. Images of the local immobilized enzyme activity obtained both by ECL and generator/collector (GC) mode of SECM were compared to elucidate the pathway in which the SECM and SECL signals are generated.
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Genetic variants in GTF2H1 and risk of lung cancer: a case-control analysis in a Chinese population.
Lung Cancer
PUBLISHED: 03-11-2009
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GTF2H1, the p62 subunit of the multiprotein complex transcription factor IIH (TFIIH), participates in both the nucleotide excision repair process and transcription control by specifically interacting with a variety of factors important in carcinogenesis. To elucidate the role of genetic variation in GTF2H1 in the etiology of lung cancer, we conducted a case-control study of 500 incident lung cancer cases and 517 controls in a Chinese population by genotyping six common single nucleotide polymorphisms (SNPs) in GTF2H1. An increased risk was associated with the variant genotypes of rs3802967 [adjusted odds ratio (OR)=1.38, 95% confidence interval (CI)=1.04-1.82], rs4150606 (adjusted OR=1.44, 95% CI=1.08-1.92), and rs4150678 (adjusted OR=1.37, 95% CI=1.04-1.81) in a dominant genetic model. The risk for rs3802967C/T+T/T genotypes was more pronounced among males subjects (P=0.002). In contrast, a decreased risk was associated with the rs4150667T/T genotype (adjusted OR=0.59, 95% CI=0.38-0.93) in a recessive model. Haplotype analysis showed that the haplotype "222212" (1 for common alleles and 2 for minor alleles) was associated with increased risk of lung cancer (P=0.03). Further evaluation using luciferase reporter constructs showed that the T allele of rs3802967 had higher luciferase expression, suggesting that the -79C-->T change may affect transcriptional activation of GTF2H1. Taken together, these results suggest that GTF2H1 polymorphisms/haplotypes may contribute to genetic susceptibility to lung cancer.
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Common variants of four bilirubin metabolism genes and their association with serum bilirubin and coronary artery disease in Chinese Han population.
Pharmacogenet. Genomics
PUBLISHED: 02-25-2009
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Studies have revealed an inverse relationship between serum total bilirubin (TBIL) levels and coronary artery disease (CAD). This study investigated the genetic variants of four bilirubin metabolism genes--heme oxygenase-1 (HMOX1), biliverdin reductase A (BLVRA), solute carrier organic anion transporter family member 1B1 (SLCO1B1), and uridine diphosphate glycosyltransferase 1A1 (UGT1A1)--in relation to TBIL levels and CAD.
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[Protective effect of lipoxin A4 against rhabdomyolysis-induced acute kidney injury in rats].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
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To investigate the protective effect of lipoxin A4 (LXA(4);) against rhabdomyolysis-induced acute kidney injury (AKI) and the possible mechanism.
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Transcriptional network analysis identifies BACH1 as a master regulator of breast cancer bone metastasis.
J. Biol. Chem.
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The application of functional genomic analysis of breast cancer metastasis has led to the identification of a growing number of organ-specific metastasis genes, which often function in concert to facilitate different steps of the metastatic cascade. However, the gene regulatory network that controls the expression of these metastasis genes remains largely unknown. Here, we demonstrate a computational approach for the deconvolution of transcriptional networks to discover master regulators of breast cancer bone metastasis. Several known regulators of breast cancer bone metastasis such as Smad4 and HIF1 were identified in our analysis. Experimental validation of the networks revealed BACH1, a basic leucine zipper transcription factor, as the common regulator of several functional metastasis genes, including MMP1 and CXCR4. Ectopic expression of BACH1 enhanced the malignance of breast cancer cells, and conversely, BACH1 knockdown significantly reduced bone metastasis. The expression of BACH1 and its target genes was linked to the higher risk of breast cancer recurrence in patients. This study established BACH1 as the master regulator of breast cancer bone metastasis and provided a paradigm to identify molecular determinants in complex pathological processes.
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Simultaneous determination of jasmonic acid epimers as phytohormones by chiral liquid chromatography-quadrupole time-of-flight mass spectrometry and their epimerization study.
J Chromatogr A
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Jasmonic acid (JA) is an essential plant hormone involved in plant development and defense system. There are four stereoisomeric forms of JA and they act quite differently in vivo. In this work, a normal phase liquid chromatography-quadrupole time-of-flight mass spectrometry (NPLC-QTOF-MS) method using cellulose tris (4-methylbenzoate) coated silica gel as the chiral stationary phase was first established for the simultaneous discrimination and direct analysis of all the four JA stereoisomers without need of derivatization. A non-endogenous JA stereoisomer was introduced as the internal standard to ensure the reliability of the developed method. Satisfactory results were obtained in terms of sensitivity (limit of detection, 0.5 ng mL(-1) or 2.4 fmol), linearity (R(2)=0.9996) and repeatability (run-to-run RSD of migration time and peak area, 0.37% and 5.9%, respectively, n=6). Endogenous rise of two natural JA stereoisomers was detected in tobacco leaves and their variations in response to mechanical wounding were monitored. In addition, the configurational stability of JA stereoisomers was investigated using the stereoisomerically pure forms which were not commercially available but easily obtained by our semi-preparative chiral LC method. Experimental evidence indicated that both of the two naturally existing JA stereoisomers were putative signals for wounding response, and the epimerization between them was not a spontaneous process simply promoted by the thermodynamical instability as expected before.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.