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71.
We describe the application of allele-specific PCR (AS-PCR) for screening biallelic markers, including SNPs, within the nonrecombining region of the human Y-chromosome (NRY). The AS-PCR method is based on the concept that the perfectly annealed primer-template complex is more stable, and therefore, more efficiently amplified under the appropriate annealing temperature than the complex with a mismatched 3'-residue. Furthermore, a mismatched nucleotide at the primer's 3'-OH end provides for a poor extension substrate for Taq DNA polymerase, allowing for discrimination between the two alleles. This method has the dual advantage of amplification and detection of alleles in a single expeditious and inexpensive procedure. The amplification conditions of over 50 binary markers, mostly SNPs, that define the major Y-haplogroups as well as their derived lineages were optimized and are provided for the first time. In addition, artificial restriction sites were designed for those markers that are not selectively amplified by AS-PCR. Our results are consistent with allele designations derived from other techniques such as RFLP and direct sequencing of PCR products. 相似文献
72.
Xiao-Ye Jin Wei Cui Chong Chen Yu-Xin Guo Xing-Ru Zhang Guo-Hui Xing Jiang-Wei Lan Bo-Feng Zhu 《Electrophoresis》2020,41(13-14):1230-1237
Compound marker consists of two different types of genetic markers, like deletion/insertion polymorphism and single nucleotide polymorphism in the genomic region of 200 bp, and microhaplotype consists of a series of closely linked single nucleotide polymorphisms in a small DNA segment (<300 bp), which show great potential for human identifications and mixture analyses. In this study, we initially selected 23 novel genetic markers comprising 10 microhaplotypes and 13 compound markers according to previously reported single nucleotide polymorphism or deletion/insertion polymorphism loci. Genetic distributions of these 23 loci in different continental populations showed that they could be used as valuable loci for forensic human identification purpose. Besides, high informativeness values (>0.1) were observed in six loci which could be further employed for forensic ancestry analyses. Finally, 18 loci were successfully developed into a multiplex panel and detected by the next generation sequencing (NGS) technology. Further analyses of these 18 loci in the studied Shaanxi Han population showed that 15 loci exhibited relatively high expected heterozygosities (>0.5). Cumulative power of discrimination (0.999 999 999 99 4835) of these 18 loci revealed that the multiplex panel could also be utilized for human identifications in the studied Shaanxi Han population. 相似文献
73.
《Analytical letters》2012,45(18):2941-2953
Randomly amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to analyze the genetic stability of ten local cultivars collected from nine districts of Manipur, India with the released ginger variety Nadia. A total of 15 RAPD and 8 ISSR primers resulted in 107 and 53 distinct and reproducible bands, respectively. A lack of polymorphism revealed the genetic stability among the local cultivars. Unlike molecular markers, analysis of essential oil composition by gas chromatography–mass spectrometry (GC-MS) revealed variation among 11 clones. Among eight major constituents obtained by GC-MS technique, cinnamyl acetate was found only in IBSD/Z-41d cultivars, whereas, in IBSD/Z-41o no trace of trans-geraniol was observed. Moreover, concentration of 6-gingerol determined by high-performance liquid chromatographic (HPLC) method shows that IBSD/Z-41r contains the highest and IBSD/Z-41i contains the lowest gingerol percentage. 相似文献
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76.
Emmanuel Letsyo 《Journal of separation science》2022,45(4):960-967
The nutritional and medicinal properties of honey have been well-documented. However, honey has occasionally been contaminated with hepatotoxic pyrrolizidine alkaloids as a result of bees foraging on the flowers of pyrrolizidine alkaloid plants. This study establishes a simple and rapid method to determine the marker pyrrolizidine alkaloids in honey using high-performance counter-current chromatography and an off-line electrospray ionization-tandem mass spectrometry, in order to identify the botanical sources responsible for the contamination. The honey sample was initially liquid-liquid extracted (sulfuric acid/hexane, 2:3, v/v) to enrich the pyrrolizidine alkaloids and subsequently purified by a semi-preparative high-performance counter-current chromatography using a solvent system, hexane/butanol/1% aqueous ammonia, 1:1:2, v/v, based on partition coefficient measurements of the target alkaloids. The recovered fractions were profiled by injecting them sequentially into an off-line electrospray ionization-tandem mass spectrometry device to monitor the preparative molecular weight based on elution and extrusion modes. The monitored lycopsamine-type pyrrolizidine alkaloids and their N-oxides (m/z 300, 316; lycopsamine, intermedine, rinderine, and echinatine) were used as the phytochemical markers to identify plants like Chromolaena odorata, Ageratum spp., or Heliotropium spp. to be responsible for the pyrrolizidine alkaloid contamination. Identification of these pyrrolizidine alkaloid plants could guide beekeepers in locating their beehives in order to minimize their potential liver damaging effects. 相似文献
77.
Emanuela Trovato Federica Vento Donato Creti Paola Dugo Luigi Mondello 《Molecules (Basel, Switzerland)》2022,27(7)
The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography–mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity. 相似文献
78.
In the present study, a cognitive self-assembled fluorescent chemosensor, (2-hydroxy-naphthalene-1-ylmethylene)-hydrazide (NIZ) was presented which disclosed sensitive and selective trace quantity detection of strong volatile acids both in binary solvent mixture [2:8 (v/v) THF/water] and solid state (thin film) based on aggregation-induced emission (AIE) characteristics. In molecularly dissolved state, NIZ participated in the excited-state intramolecular proton transfer (ESIPT), where the dynamic flexibility during a fast photoinduced process debilitated the consumed excited energy nonradiatively and enabled NIZ to be completely nonluminescent in THF (φf = 0.39%). However, vigorous rigidification of molecular framework upon exercising different noncovalent forces obstructed all possible intramolecular motions via restricted intramolecular rotation (RIR), where delimited ESIPT upon prompting the molecules into self-assembly resulted dramatically augmented emission intensity (φf = 29.8%) impregnated with AIE behavior in THF/water. Subsequently, spontaneously evolved green emissive fluorescent nanoaggregates were primarily employed as a fluorescent chemosensor for aqueous phase recognition of strong acids where protonation-induced destruction of aggregated morphology due to reasonable interaction between NIZ and analytes led to a selective fluorescence quenching towards trifluoroacetic acid [(HTFA); detection limit (DL) = 41.74 nM], hydrochloric acid [(HCl); DL = 47.47 nM] and nitric acid [(HNO3); DL = 50.17 nM). Importantly, the ready-made cost-effective test kits of NIZ exhibited a selective fluorogenic response towards vapors from HNO3, HTFA and HCl in the rapid fashion where DLs were as low as 0.88, 1.39 and 4.57 ppm respectively to demonstrate the “in-the field” monitoring of air quality. Finally, the reversible “ON-OFF” fluorogenic response from NIZ inspired us to device a “use” and “throw” security marker upon alternative presence of HTFA and triethylamine (TEA) to augment the day-to-day practical applications. 相似文献
79.
80.
Employing one- plus two-body random matrix ensembles for bosons, temperature and entropy are calculated, using different definitions, as a function of the two-body interaction strength λ for a system with 10 bosons (m=10) in five single-particle levels (N=5). It is found that in a region λ∼λt, different definitions give essentially the same values for temperature and entropy, thus defining a thermalization region. Also, (m,N) dependence of λt has been derived. It is seen that λt is much larger than the λ values where level fluctuations change from Poisson to GOE and strength functions change from Breit–Wigner to Gaussian. 相似文献