Review on recent and advanced applications of monoliths and related porous polymer gels in micro-fluidic devices

This review critically summarises recent novel and advanced achievements in the application of monolithic materials and related porous polymer gels in micro-fluidic devices appearing within the literature over the period of the last 5 years (2005-2010). The range of monolithic materials has developed rapidly over the past decade, with a diverse and highly versatile class of materials now available, with each exhibiting distinct porosities, pore sizes, and a wide variety of surface functionalities. A major advantage of these materials is their ease of preparation in micro-fluidic channels by in situ polymerisation, leading to monolithic materials being increasingly utilised for a larger variety of purposes in micro-fluidic platforms. Applications of porous polymer monoliths, silica-based monoliths and related homogeneous porous polymer gels in the preparation of separation columns, ion-permeable membranes, preconcentrators, extractors, electrospray emitters, micro-valves, electrokinetic pumps, micro-reactors and micro-mixers in micro-fluidic devices are discussed herein. Procedures used in the preparation of monolithic materials in micro-channels, as well as some practical aspects of the micro-fluidic chip fabrication are addressed. Recent analytical/bioanalytical and catalytic applications of the final micro-fluidic devices incorporating monolithic materials are also reviewed.     

Isolation and characterization of a new subunit of phycocyanin from Chroomonas placoidea

A new phycocyanin（PC） fluorescent subunit namedβ₂（18kDa） was isolated and characterized by both SDS-PAGE and isoelectric focusing（IEF） from a species of cryptophytic alga Chroomonas placoidea.PC was separated and purified by ammonium sulfate sedimentation followed by two steps of Sephadex G-100 chromatography.After denatured in 4 mol/L urea for 48 h,PC was divided into two fractions by passing through a Sephacryl S-100 chromatography column twice.The blue fraction（S-1） containedβsubunits with a maximal absorbance at 595 nm in visible light region.While the green fraction（S-2） enriched inαsubunits showed a characteristic long wavelength absorbance at 680-700 nm region and exhibited a relatively low molecular weight of 9.4（α₁） and 8.5 kDa（α₂）.Fraction S-1 also consisted of two different fluorescent subunits with molecular weight of 20.1 kDa（β₁） and 18 kDa （β₂） and differed from each other on isoelectric points of pH 5.7（ft） and 6.0（ft）,respectively.Further investigation of peptide sequence will help a lot in elucidating the new subunit ft that was smaller in size and more neutral than the known ft subunit,and may provide an alternative explanation in structure of cryptophytic phycobiliproteins.     

On-line coupling of gel electrophoresis and inductively coupled plasma-mass spectrometry

The on-line coupling of gel electrophoresis with inductively coupled plasma-mass spectrometry (GE-ICP-MS) is a powerful tool for simultaneous separation, detection and quantification of bio-molecules, and has been applied to the determination of phosphorus in DNA, phosphoproteins, and phosphopeptides, gold in nano-particles, iron in metalloproteins, and iodine in aerosols, and cisplatin-oligonucleotide interactions. However, since the first report in 2005, relatively few papers have been published, perhaps reflecting the lack of familiarity with the benefits of this promising methodology. So, here for the first time, we critically review the applications of GE-ICP-MS, and explore the advantages and the limitations of the technique for various applications. Such scrutiny may be useful in not only the development of the technique but also highlighting its potential in proteomics, genomics and metallomics.     

Capillary and gel electromigration techniques and MALDI-TOF MS – Suitable tools for identification of filamentous fungi

Microbial strains are now spreading out of their original geographical areas of incidence and previously adequate morphological identification methods often must be accompanied by a phenotypic characterization for the successful microbial identification. The fungal genus Monilinia represents a suitable example. Monilinia species represent important fruit pathogens responsible for major losses in fruit production. Four closely related spp. of Monilinia: Monilinia laxa, Monilinia fructigena, Monilinia fructicola and Monilia polystroma have been yet identified. However, the classical characterization methods are not sufficient for current requirements, especially for phytosanitary purposes.     

采用高效液相色谱-质谱考察家福捕鸟蛛粗毒中多肽和蛋白质的多样性

家福捕鸟蛛(Selenocosmia jiafu)是一种生活在中国广西、云南等边远山区、中等个体、产毒量较大和毒性较强的蜘蛛新种。为了对家福捕鸟蛛粗毒成分进行初步探索,采用反相高效液相色谱、基质辅助激光解吸离子化飞行时间质谱和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳方法对粗毒多肽和蛋白质的多样性进行了分析。结果表明:家福捕鸟蛛粗毒经色谱分离后得到40多个色谱峰,经质谱鉴定得到238个多肽,且多肽的相对分子质量呈现出双峰分布,其中62.5%的多肽的相对分子质量分布在3000~4500 之间,33.2%的多肽的相对分子质量分布在1000~3000之间。这种相对分子质量的分布模式不同于其他已经报道的蜘蛛粗毒中多肽的分布模式。电泳分析结果表明:除了相对分子质量在10000以下的多肽分子,粗毒在50、72和90 kD附近有3条明显的条带,粗毒电泳条带经液相色谱-电喷雾四极杆飞行时间质谱鉴定,主要是一些血蓝蛋白、钾离子通道蛋白、钙蛋白酶等。说明家福捕鸟蛛粗毒中多肽和蛋白质种类丰富。     

Total metal concentrations in serum of dialysis patients and fractionation of Cu, Rb, Al, Fe and Zn in spent continuous ambulatory peritoneal dialysis fluids

Total metal concentrations were determined in the serum of 12 continuous ambulatory peritoneal dialysis (CAPD) patients and in fresh and spent CAPD fluids by electrothermal and flame atomic absorption spectrometry (ETAAS, FAAS). Concentrations of Cu in serum of CAPD patients ranged from 720 to 1780 ng cm⁻³, Rb from 128 to 346 ng cm⁻³, Al from 10 to 72 ng cm⁻³, Fe from 800 to 2300 ng cm⁻³ and Zn from 659 to 1310 ng cm⁻³. The accuracy of the analytical procedure was checked by the analysis of the reference material Seronom™, Trace Elements in Serum. Good agreement between the certified and determined values was obtained for Al, Cu, Fe and Zn. The data on the total metal concentrations in CAPD fluids indicated that during CAPD fluid exchange the losses of Cu from 5.0 to 35 ng cm⁻³, of Rb from 50 to 110 ng cm⁻³ and of Al from 3.0 to 14.0 ng cm⁻³ occurred through the peritoneal membrane. Although fresh CAPD fluids contained traces of Fe (3.0-5.0 ng cm⁻³), the transfer of this element took place through the peritoneal membrane into spent CAPD fluid (13.0-38.0 ng cm⁻³). Zn concentrations were in general lower in spent (20.0-80 ng cm⁻³) than in fresh CAPD fluids (∼100 ng cm⁻³). To follow the mechanisms of the transfer of trace elements through the peritoneal membrane of CAPD patients, fractionation of metals was carried out in spent CAPD fluids by size exclusion chromatography with UV and AAS detection, applying Superdex HR 10/30 column. The chromatographic run was followed at 278 nm and separated metal species also determined ‘off line’ in 1 cm³ fractions by ETAAS or FAAS. From the UV chromatograms and AAS analysis of trace elements in the separated fractions it was demonstrated that Cu, Al, Fe and Zn were bound to proteins and only partially to low molecular weight (LMW) species, while Rb was associated exclusively with LMW species. For characterisation of the high molecular weight (HMW) binding proteins, fractions containing trace elements were subjected to SDS-PAGE electrophoresis. Al and Fe were presumably bound to transferrin, but due to its low concentration in spent CAPD fluids, it was not possible to confirm its presence in the separated fractions. About 10% of Al and 15% of Fe corresponded to LMW species. A fraction of HMW proteins of Cu in spent CAPD fluids was most probably bound to albumin and Zn to albumin and globulins. About 50% of Cu and Zn existed in LMW proteins, while Zn was also found partially in ionic form.     

浙江萧山、舟山和福建集美臭锄血红蛋 白、血清蛋 白电泳比较研究

本文用血红蛋白的薄层等电聚焦技术对浙江萧山、舟山和福建集美的三地臭蒯进行比较，结果显示:大陆(萧山与集美)和海岛(舟山)之间的带谱存在差异.大陆有s条区带，海岛的带谱变化较大，存在四种不同类型.用血清蛋白的SDS-聚丙烯酞胺凝胶电泳技术和血清蛋白的薄层等电聚焦技术对上述三地臭渝的分析表明:海岛个体血清蛋白的成份和在血液中相对含量较大陆为少，而大陆萧山和集美的血清蛋白在血液中的相对含量和成份亦略有不同.     

明胶中α、β和γ三种构象的全分析

由文献表明:迄今为止,用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)测定明胶分子量分布,只能分出<α,α₁,α₂和β组份,而γ及>γ的组份未能检出。也就是说,大约30万以上的分子量组份未能进入凝胶板内(以下简称“入板”)。这对明胶构象的全分析和对明胶质量的正确判断是一个严重的缺陷。 本文主要探讨和研究γ及>γ组份的入板问题。所采取的方法是:控制丙烯酰胺和甲叉丙烯酰胺(交联剂)的相对含量,选择合适的交联度梯度,使之既适用于α和β组份迁移,也能让γ及>γ的组份入板。此外,在小的交联度和大孔径的情况下,还能符合凝胶板对凝胶强度的基本要求。     

Discovery of conversion driven by β-glucuronidase from flavone glycoside to aglycone and application in identifying the raw Scutellariae Radix

Scutellariae Radix (SR), the dried root of Scutellaria baicalensis Georgia, is a famous Chinese materia medica that has been widely employed. Raw Scutellariae Radix (RSR), steamed Scutellariae Radix (SSR), and wine Scutellariae Radix (WSR) are adopted for use in clinical practice. Because of their easily confused appearance, they are always misused. Aiming at this problem, an ultra performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method was established to survey misuse of the RSR and the processed SR (SSR and WSR) in the market by employing baicalin (BC), wogonoside (WS), baicalein (BN), and wogonin (WN) as quality indicators. Fortunately, β-glucuronidase, which mediates conversion from flavone glycoside to aglycone, was identified in the RSR samples by the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The significant production of BN and WN was witnessed in the RSR samples, which did not occur in the SSR and WSR samples in virtue of the inactivated β-glucuronidase. Besides, the different capacities of β-glucuronidase were evaluated in the tested samples. In general, we provided the first evidence to scientifically identify RSR from SSR and WSR.     

SDS-聚丙烯酰胺凝胶圆盘电泳法分离乳酸脱氢酶

用连续的和不连续的ＳＤＳ－聚丙烯胺凝胶圆盘电泳法（ＳＤＳ－ＰＡＧＥ）对乳酸氢酶进行了电泳分离,获得了乳酸脱氢酶同功酶的清晰分离带,证明了不连续的ＳＤＳ－聚丙烯酰胺凝胶圆盘电泳法其分离效果优于连续的ＳＤＳ－聚丙烯酰交圆盘电泳法。