Four chrysanthemum cultivars were generated through (carbon) ion-beam irradiation of the original ‘Jimba’ ( Chrysanthemum morifolium Ramat.). The new cultivars had acquired a number of superior cultivation traits, while remaining identical to the commercially available ‘Jimba’ in appearance. In this study, polymerase chain reaction (PCR) assays were used to detect the mutated region of each strain, thereby allowing clear identification at the molecular level. PCR assays were performed with 446 primer sets, including random amplified polymorphic DNA (RAPD) primer sets (10-mer RAPD), arbitrarily primed (AP)-PCR primers based on retrotransposon-like sequences and modified RAPD primers (15-mer RAPD). 15-mer RAPD primers generated a 1.49-fold increased band number at high annealing temperatures compared with the original 10-mer RAPD primers and could thus be effective for detection of polymorphic patterns. Our results provide information on the mutated regions of these ion-beam-irradiated chrysanthemum cultivars. Thus, specific DNA markers could be used to improve identification of new cultivars of chrysanthemum as well as other clonal cultivars of horticultural and agricultural crops.
Changwu Lv,Zhenhong Jia,Jie Lv,Hongyan Zhang,Yanyu Li
N-type macroporous silicon microcavity structures were prepared using electrochemical etching in an HF solution in the absence of light and oxidants. The CdSe/ZnS water-soluble quantum dot-labeled DNA target molecules were detected by monitoring the microcavity reflectance spectrum, which was characterized by the reflectance spectrum defect state position shift resulting from changes to the structures’ refractive index. Quantum dots with a high refractive index and DNA coupling can improve the detection sensitivity by amplifying the optical response signals of the target DNA. The experimental results show that DNA combined with a quantum dot can improve the sensitivity of DNA detection by more than five times.Keywords:N-type porous silicon;quantum dot labeling;QD-DNA;reflectance spectrum
Salbutamol (SAL) is known as quick-acting β-2 receptor agonist and its use in humans for pulmonary diseases and/or in animal feed is limited because of associated potential hazardous effects on health. Several techniques are available for the detection of SAL, but are expensive and time consuming. Here for the first time, a novel pre-assembled DNA immunoprobe-based immuno-PCR assay was developed to investigate the levels of SAL in human urine samples and compared the proposed immuno-PCR assay for the detection of SAL with that of direct competitive ELISA. Under the optimized conditions, the assay showed a linear range over seven orders of magnitude, whereas the limit of detection of SAL in buffer was found to be 21 fg/mL. Current immuno-PCR assay exhibited a 300-fold better detection limit for SAL as compared to one achieved with direct competitive ELISA using the same antibody. In conclusion, it has been found that the developed method is highly sensitive and simple method that can significantly enhance the detection sensitivity for small molecules. Moreover it can be modified and used for detecting other small molecules and/or chemicals that exist in the environment and are responsible for the environmental pollution.
In this paper, a novel turn-on fluorescence aptasensor has been designed for adenosine detection based on fluorescence resonance energy transfer (FRET) from single-stranded DNA labeled carbon dots (ssDNA-CDs) to aptamer modified gold nanoparticles (aptamer-AuNPs). In the absence of adenosine, the fluorescence of ssDNA-CDs was quenched by aptamer-AuNPs via the formation of an aptamer–ssDNA duplex. The introduced adenosine competed to displace ssDNA-CDs by specifically binding to the aptamer, resulting in the recovery of the quenched fluorescence of ssDNA-CDs. Under optimized conditions, the increase in fluorescence intensity was proportional to the concentration of adenosine with a linear range of 10–500 nM and allowed a limit of detection as low as 4.2 nM. In addition, this method was successfully applied to adenosine determination in human serum samples with satisfactory results.
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