Using light to bioactivate surfaces: A new way of creating oriented, active immunobiosensors

Ultraviolet light can be used to immobilize biomolecules onto thiol reactive surfaces in order to, e.g., make biosensors. The mechanism involves light-induced formation of free, reactive thiol groups in disulphide containing molecules. This technology allows for the creation of arrays of biomolecules with a high degree of reproducibility, circumventing the need for often expensive nano/micro-dispensing technologies. The ultimate size of the immobilized spots is defined by the focal area of the UV beam. Light-induced immobilization has the added benefit that the immobilized molecules will be spatially oriented and covalently bound to the surface. In this paper, we demonstrate the utility of a sensor array created with the new sensor technology when integrated into a microfluidic system. Protein arrays made using light-induced immobilization showed successful antigen/antibody binding in a flow cell allowing the visualisation of real time binding and enzyme activity. This new technology is ideal for the creation of protein/DNA microarrays, can replace present micro-dispensing arraying technologies and is ideal as a molecular imprinting technology.     

IC制造中的危害和预防

本文论述了关于IC制造中使用的工艺气体和厂房设施、生产设备的危害及防护。     

Selection of phage-displayed antibodies with high affinity and specificity by electrophoresis in microfluidic devices

A method development aimed for high-throughput and automated antibody screening holds great potential for areas ranging from fundamental molecular interactions to the discovery of novel disease markers, therapeutic targets, and monoclonal antibody engineering. Surface display techniques enable efficient manipulation of large molecular libraries in small volumes. Specifically, phage display appeared as a powerful technology for selecting peptides and proteins with enhanced, target-specific binding affinities. Here, we present a phage-selection microfluidic device wherein electrophoresis was performed under two orthogonal electric fields through an agarose gel functionalized with the respective antigen. This microdevice was capable of screening and sorting in a single round high-affinity phage-displayed antibodies against virus glycoproteins, including human immunodeficiency virus-1 glycoprotein 120 or the Ebola virus glycoprotein (EBOV-GP). Phages were differentially and laterally swept depending on their antigen affinity; the high-affinity phages were recovered at channels proximal to the application site, whereas low-affinity phages migrated distal after electrophoresis. These experiments proved that the microfluidic device specifically designed for phage-selection is rapid, sensitive, and effective. Therefore, this is an efficient and cost-effective method that allowed highly controlled assay conditions for isolating and sorting high-affinity ligands displayed in phages.     

Phospho‐l‐tyrosine‐agarose chromatography: Adsorption of human IgG and its proteolytic fragments

The behavior of human immunoglobulin G (IgG) and antigen‐binding fragment (Fab fragment) adsorption onto phospho‐l ‐tyrosine immobilized on agarose (P‐Tyr‐agarose) was evaluated by pseudoaffinity chromatography. The effects of buffer systems MES, MOPS, Bis–Tris, Tris–HCl and sodium phosphate (NaP) and pH on IgG adsorption were studied and high purity values were obtained (96%, based on ELISA analysis of albumin, transferrin and immunoglobulins A, G and M) when IgG was purified from human plasma diluted in 10 mmol L^?1 NaP buffer at pH 6.0. The capture of IgG by the P‐Tyr‐agarose was also promising, since 91% of the IgG was adsorbed when plasma was diluted in 25 mmol L^?1 MES buffer at pH 5.5, recommending its use for IgG depletion from human plasma under this condition. The experimental data on IgG adsorption kinetics were in agreement with the pseudo‐second‐order model. The adsorption isotherm data were well described by the Langmuir–Freundlich model with the value of parameter n being <1 (0.72), indicating negative cooperativity. Selectivity was achieved on P‐Tyr‐agarose from digested human IgG in HEPES 25 mmol L^?1 buffer at pH 7.0 where Fab fragments were obtained in eluted fractions without Fc fragments (but with uncleaved IgG) with 86.2% recovery.     

Synthesis and Characterization of New Ortho-Acetyl or Ortho-bis- p -aminophenoxy Phosphonate Monomers

Some new aryl phosphonic acid ethyl ester analogs of acetyl salicylic acids, and bis- p -aminophenoxy-benzo-phosphonic acid ethyl esters have been prepared in good yield. Characterization by spectroscopic techniques indicates that in the phosphorus NMR spectra a significant change in chemical shift values between the starting phenolic phosphonate and both the corresponding derivative is observed; thus this up-field shift is very diagnostic for this type of compounds.     

Microchip electrophoresis-SDS methods with high-resolution and silver stain sensitivity for quality screening and quantitation of protein products

Two microchip electrophoresis (ME)-SDS methods have been developed for high throughput quantitation and quality screening of protein products. Both methods utilize a commercial microchip instrument to separate dodecyl sulfate-coated proteins within 1 min. In the high-resolution ME-SDS method, improved separation selectivity is achieved using a mixture of sieving polymers. Proteins of similar sizes, such as different fragment antigen-binding (Fab) assemblies can be readily resolved and individually quantified. A high-sensitivity ME-SDS method was also developed with sensitivity comparable to that of SDS-PAGE with silver staining. In this method, protein molecules are derivatized with a fluorescence reagent prior to analysis. LIF detection of the covalently attached fluorophore enables accurate quantitation of low-expressing proteins and detection of minor species at 0.04% level (1 ng/mL loading concentration). Both the high-resolution and the high-sensitivity ME-SDS methods can be applied to crude fermentation samples. The utilities of these methods in process development and formulation stability study are presented.     

MEMS成为超越摩尔定律的突破口

半导体技术在摩尔定律上似乎走入了瓶颈期,而超越摩尔定律的新兴技术却受到了众多公司的青睐,其中MEMS以无处不在的应用潜力攫取了业界大大小小公司的眼球。日前,在由上海微系统与信息技术研究所、传感技术国家重点实验室、《半导体国际》、     

MES系统及其在半导体制造中的应用

本文叙述了MES 系统的定义,半导体制造前工序中的MES 系统的特点,各组成模块的功能,系统的软硬件要求等。并指出了其在半导体制造中的应用。     

IC厂房洁净系统方案介绍及比较

微电子工业迅猛发展,本文以一个典型的IC厂房为实例,介绍几种洁净设计方式,并从投资、施工、运行等方面进行分析比较。     

半导体晶圆车间的成本控制方法

由于市场对专用集成电路需求的猛增，大多数半导体企业都已采用面向订单的混合生产方式，其车间设施具有一定的柔性，能同时生产多种类型的晶圆；再加上CIM与价格昂贵、自动化程度极高的晶圆加工设备的广泛运用，引起了晶圆车间成本构成中直接人工费用大幅度减少和间接费用呈多样化巨增，因此晶圆制造车间已开始改变为从工程学、技术层向去把握成本信息，以工程经济学的方法对成本进行预测、监控，因为在晶圆制造车间中，成本绝非单纯是会计帐簿上的产物，而是在制造过程中的逐道工序中产生的。