共查询到4条相似文献，搜索用时 15 毫秒
1.
《Electrophoresis》2017,38(8):1175-1178
Silver staining is one of the widely used methods for DNA fragment detection in biological research. Silver staining protocols have been steadily optimized to improve detection efficiency. This research reports a continuous effort to simplify the existing silver staining protocols, lower experiment cost, and improve DNA detection sensitivity and image clarity. The new method only requires three reagents (silver nitrate, sodium hydroxide, and formaldehyde) and 6–7 min with high detection sensitivity to visualize as low as 14.6 pg (3.3 pg/mm2) of DNA in a non‐denaturing polyacrylamide gel. In comparison to previous reported protocols, the new one has the highest resolution, is the easiest to operate, takes the shortest time, and uses the fewest chemical reagents. Therefore, the new method can be used for quick generation of high quality molecular marker data in genetic analysis. 相似文献
2.
Mohammad Hossein Pournaghi‐Azar Mohammad Saeid Hejazi Esmaeel Alipour 《Electroanalysis》2007,19(4):466-472
The human interleukine‐2 gene (hIL‐2) is detected with a label‐free DNA hybridization biosensor using a non‐inosine substituted probe. The sensor relies on the immobilization of a 20‐mer antisense single strand oligonucleotide (chIL‐2) related to the human interleukine‐2 gene on the pencil graphite electrode (PGE) as a probe. The guanine oxidation signal was monitored using anodic differential pulse voltammetry (ADPV). The electrochemical pretreatment of the polished PGE at 1.80 V for 5 min is suggested. Then, 5 min immobilization at 0.50 V was found as the optimum condition for immobilization of the probe. The electrochemical detection of hybridization between chIL‐2 and hIL‐2 as a target was accomplished. The selectivity of the biosensor was studied using noncomplementary oligonucleotides. Diagnostic performance of the biosensor is described and the detection limit is found 36 pg/μL. 相似文献
3.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(12):1078-1086
The crystallization and characterization of a new polymorph of 2‐thiouracil by single‐crystal X‐ray diffraction, Hirshfeld surface analysis and periodic density functional theory (DFT) calculations are described. The previously published polymorph (A ) crystallizes in the triclinic space group P , while that described herein (B ) crystallizes in the monoclinic space group P 21/c . Periodic DFT calculations showed that the energies of polymorphs A and B , compared to the gas‐phase geometry, were −108.8 and −29.4 kJ mol−1, respectively. The two polymorphs have different intermolecular contacts that were analyzed and are discussed in detail. Significant differences in the molecular structure were found only in the bond lengths and angles involving heteroatoms that are involved in hydrogen bonds. Decomposition of the Hirshfeld fingerprint plots revealed that O…H and S…H contacts cover over 50% of the noncovalent contacts in both of the polymorphs; however, they are quite different in strength. Hydrogen bonds of the N—H…O and N—H…S types were found in polymorph A , whereas in polymorph B , only those of the N—H…O type are present, resulting in a different packing in the unit cell. QTAIM (quantum theory of atoms in molecules) computational analysis showed that the interaction energies for these weak‐to‐medium strength hydrogen bonds with a noncovalent or mixed interaction character were estimated to fall within the ranges 5.4–10.2 and 4.9–9.2 kJ mol−1 for polymorphs A and B , respectively. Also, the NCI (noncovalent interaction) plots revealed weak stacking interactions. The interaction energies for these interactions were in the ranges 3.5–4.1 and 3.1–5.5 kJ mol−1 for polymorphs A and B , respectively, as shown by QTAIM analysis. 相似文献
4.
Silicones have innumerable applications in many areas of life. Polydimethylsiloxane (PDMS), which belongs to the class of silicones, has been extensively used in the field of analytical chemistry owing to its favourable physicochemical properties. The use of PDMS in analytical chemistry gained importance with its application as a stationary phase in gas chromatographic separations. Since then it has been used in many sample preparation techniques such as solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), thin-film extraction, permeation passive sampling, etc. Further, it is gaining importance in the manufacturing of lab-on-a-chip devices, which have revolutionized bio-analysis. Applications of devices containing PDMS and used in the field of analytical chemistry are reviewed in this paper. 相似文献