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1.
Separation of Simulants of Biological Warfare Agents from Blood by a Miniaturized Dielectrophoresis Device 总被引:2,自引:0,他引:2
Ying Huang Joon Mo Yang Penelope J. Hopkins Sam Kassegne Marcus Tirado Anita H. Forster Howard Reese 《Biomedical microdevices》2003,5(3):217-225
Separation of simulants of biological warfare agents from blood using dielectrophoresis (DEP) was demonstrated in a miniaturized DEP device. The device was fabricated by laminating five different layers (all 40 mm×40 mm) including a polycarbonate substrate, a pressure sensitive acrylic adhesive (PSA) layer, a patterned polyimide layer with a flip-chip bonded dielectrophoresis chip (DEP chip), a PSA layer with microfluidic channel, and a glass cover plate. The DEP chip consisted of repetitive interdigitated electrodes with characteristic dimension of 50 m. This device was employed to separate different simulants of biological warfare agents (BWA), namely Bacillus cereus (B. cereus), Escherichia coli (E. coli) and Listeria monocytogenes (L. monocytogenes), from blood, individually or simultaneously. PCR amplification, which was inhibited by blood components in pre-separation samples, successfully revealed bands in post-separation samples containing single or multiple BWA. Up to 97% efficiency of separation was achieved as demonstrated by culturing post-separation E. coli cells. The DEP device described here can potentially be used to reduce sample complexity for detection of infectious disease pathogens and biological warfare agents. 相似文献
2.
This study reports a new perfusion-based, micro three-dimensional (3-D) cell culture platform for high-throughput cell culture
using enabling microfluidic technologies. In this work, the micro 3-D cell culture platform is fabricated based on SU-8 lithography
and polydimethylsiloxane replication processes. The micro cell culture platform can maintain homogenous and stable culture
environments, as well as provide pumping of multiple mediums and efficient cell/agarose (scaffold) loading functions, which
allows realization of more precise and high-throughput cell culture-based assays. In this study, the design of a high-throughput
medium pumping mechanism was especially highlighted. A new serpentine-shaped pneumatic micropump was used to provide the required
medium pumping mechanism. Pneumatic microchannels with a varied length and U-shape bending corners were designed to connect
three rectangular pneumatic chambers such that one can fine-tune the pumping rate of the S-shape micropump by using the fluidic
resistance. To achieve a high-throughput medium pumping function, a pneumatic tank was designed to simultaneously activate
all of the 30 pneumatic micropumps with a uniform pumping rate. Results show that the pumping rates of the 30 integrated micropumps
were statistically uniform with a flow rate ranging from 8.5 to 185.1 μl h-1, indicating the present multiple medium pumping mechanism is feasible for high-throughput medium delivery purposes. Furthermore,
as a demonstration case study, 3-D culture of oral cancer cell was successfully performed, showing that the cell viability
remained as high as 95% - 98% during the 48 h cell culture. As the result of miniaturization, this perfusion-based 3-D cell
culture platform not only provides a well-defined and stable culture condition, but also greatly reduces the sample/reagent
consumption and the need for human intervention. Moreover, due to the integrated capability for multiple medium pumping, high-throughput
research work can be achieved. These traits are found particularly useful for high-precision and high-throughput, 3-D cell
culture-based assay. 相似文献
3.
Human mesenchymal stem cells can differentiate into multiple lineages for cell therapy and, therefore, have attracted considerable
research interest recently. This study presents a new microfluidic device for bead and cell separation utilizing a combination
of T-junction focusing and tilted louver-like structures. For the first time, a microfluidic device is used for continuous
separation of amniotic stem cells from amniotic fluids. An experimental separation efficiency as high as 82.8% for amniotic
fluid mesenchymal stem cells is achieved. Furthermore, a two-step separation process is performed to improve the separation
efficiency to 97.1%. These results are based on characterization experiments that show that this microfluidic chip is capable
of separating beads with diameters of 5, 10, 20, and 40 μm by adjusting the volume-flow-rate ratio between the flows in the
main and side channels of the T-junction focusing structure. An optimal volume-flow-rate ratio of 0.5 can lead to high separation
efficiencies of 87.8% and 85.7% for 5-μm and 10-μm beads, respectively, in a one-step separation process. The development
of this microfluidic chip may be promising for future research into stem cells and for cell therapy. 相似文献
4.
P. Fikar V. Georgiev G. Lissorgues M. Holubova D. Lysak D. Georgiev 《Biomedical microdevices》2018,20(1):12
In this work, a novel force equilibrium method called distributed dielectrophoretic cytometry (2DEP cytometry) was developed. It uses a dielectrophoresis (DEP)-induced vertical translation of live cells in conjunction with particle image velocimetry (PIV) in order to measure probabilistic distribution of DEP forces acting on an entire cell population. The method is integrated in a microfluidic device. The bottom of the microfluidic channel is lined with an interdigitated electrode array. Cells passing through the micro-channel are acted on by sedimentation forces, while DEP forces either oppose sedimentation, support sedimentation, or neither, depending on the dielectric (DE) signatures of the cells. The heights at which cells stabilize correspond to their DE signature and are measured indirectly using PIV, which enables simultaneous and high-throughput collection of hundreds of single-cell responses in a single PIV frame. The system was validated using polystyrene micro-particles. Preliminary experimental data quantify the DE signatures of immortalized myelogenous leukemia cell lines K562 and KG1. We show DEP-induced cell translation along the parabolic velocity profile can be measured by PIV with sub-micron precision, enabling identification of individual cell DE signatures. DE signatures of the selected cell lines are distinguishable. Throughput of the method enables measurement of DE signatures at 10 different frequencies in almost real time. 相似文献
5.
This study reports a microfluidic cell culture chip consisting of 48 microbioreactors for high-throughput perfusion 3-dimensional
(3-D) cell culture-based assays. Its advantages include the capability for multiplexed and backflow-free medium delivery,
and both efficient and high-throughput micro-scale, 3-D cell culture construct loading. In this work, the microfluidic cell
culture chip is fabricated using two major processes, specifically, a computer-numerical-controlled (CNC) mold machining process
and a polydimethylsiloxane (PDMS) replication process. The chip is composed of micropumps, microbioreactors, connecting microchannels
and a cell/agarose scaffold loading mechanism. The performance of the new pneumatic micropumps and the cell/agarose scaffold
loading mechanism has been experimentally evaluated. The experimental results show that this proposed multiplexed medium-pumping
design is able to provide a uniform pumping rate ranging from 1.5 to 298.3 μl hr−1 without any fluid backflow and the resultant medium contamination. In addition, the simple cell/agarose loading method has
been proven to be able to load the 3-D cell culture construct uniformly and efficiently in all 48 microbioreactors investigated.
Furthermore, a micro-scale, perfusion, 3-D cell culture-based assay has been successfully demonstrated using this proposed
cell culture chip. The experimental results are also compared to a similar evaluation using a conventional static 3-D cell
culture with a larger scale culture. It is concluded that the choice of a cell culture format can influence assay results.
As a whole, because of the inherent advantages of a miniaturized perfusion 3-D cell culture assay, the cell culture chip not
only can provide a stable, well-defined and more biologically-meaningful culture environment, but it also features a low consumption
of research resources. Moreover, due to the integrated medium pumping mechanism and the simple cell/agarose loading method,
this chip is economical and time efficient. All of these traits are particularly useful for high-precision and high-throughput
3-D cell culture-based assays. 相似文献
6.
Chia-Chun Hsieh Song-Bin Huang Ping-Ching Wu Dar-Bin Shieh Gwo-Bin Lee 《Biomedical microdevices》2009,11(4):903-913
This study reports a new microfluidic cell culture platform for real-time, in vitro microscopic observation and evaluation of cellular functions. Microheaters, a micro temperature sensor, and micropumps are
integrated into the system to achieve a self-contained, perfusion-based, cell culture microenvironment. The key feature of
the platform includes a unique, ultra-thin, culture chamber with a depth of 180 μm, allowing for real-time, high-resolution
cellular imaging by combining bright field and fluorescent optics to visualize nanoparticle-cell/organelle interactions. The
cell plating, culturing, harvesting and replenishing processes are performed automatically. The developed platform also enables
drug screening and real-time, in situ investigation of the cellular and sub-cellular delivery process of nano vectors. The mitotic activity and the interaction
between cells and the nano drug carriers (conjugated quantum dots-epirubicin) are successfully monitored in this device. This
developed system could be a promising platform for a wide variety of applications such as high-throughput, cell-based studies
and as a diagnostic cellular imaging system. 相似文献
7.
Microfluidic devices are operated at a low-Reynolds-number flow regime such that the transportation and mixing of fluids are
naturally challenging. There is still a great need to integrate fluid control systems such as pumps, valves and mixers with
other functional microfluidic devices to form a micro-total-analysis-system. This study presents a new pneumatic microfluidic
rotary device capable of transporting and mixing two different kinds of samples in an annular microchannel by using MEMS (Micro-electro-mechanical-systems)
technology. Pumping and mixing can be achieved using a single device with different operation modes. The micropump has four
membranes with an annular layout and is compact in size. The new device has a maximum pumping rate of 165.7 μL/min at a driving
frequency of 17 Hz and an air pressure of 30 psi. Experimental data show that the pumping rate increases as higher air pressure
and driving frequency are applied. In addition, not only can the microfluidic rotary device work as a peristaltic pumping
device, but it also is an effective mixing device. The performance of the micromixer is extensively characterized. Experimental
data indicate that a mixing index as high as 96.3% can be achieved. The developed microfluidic rotary device can be easily
integrated with other microfluidic devices due to its simple and reliable PDMS fabrication process. The development of the
microfluidic rotary device can be promising for micro-total-analysis-systems. 相似文献
8.
Conventional in vitro cell culture that utilizes culture dishes or microtiter plates is labor-intensive and time-consuming, and requires technical
expertise and specific facilities to handle cell harvesting, media exchange and cell subculturing procedures. A microfluidic
array platform with eight microsieves in each cell culture chamber is presented for continuous cell culture. With the help
of the microsieves, uniform cell loading and distribution can be obtained. Within the arrays, cells grown to the point of
confluency can be trypsinized and recovered from the device. Cells trapped in the microsieves after trypsinization function
to seed the chambers for subsequent on-chip culturing, creating a sustainable platform for multiple cycles. The capability
of the microfluidic array platform was demonstrated with a BALB/3T3 (murine embryonic fibroblast) cell line. The present microfluidic
cell culture platform has potential to develop into a fully automated cell culture system integrated with temperature control,
fluidic control, and micropumps, maximizing cell culture health with minimal intervention. 相似文献
9.
Chun-Che Lin Chin-Chung Tseng Chao-June Huang Jung-Hao Wang Gwo-Bin Lee 《Biomedical microdevices》2010,12(5):887-896
This study presents an integrated microfluidic chip for non-immunologically determining the concentrations of albumin in clinical
urine samples. This microchip integrates membrane-type micromixers and a fan-shaped micropump capable of simultaneously and
precisely delivering assay reagents to react with 6 urine samples in one single operation. The experimental results show that
the coefficient of variation in the pumping rate is 2.42%. More importantly, using this unique chip design, only 2 electromagnetic
valves are required for the actuation of the micromixer and the micropump. The working range of the proposed microchip is
2–200 mg/L of albumin, which covers the range of interest for the determination of microalbuminuria. Moreover, statistical
analysis show that the results obtained by the proposed microchip are in good agreement with the conventional detection method,
based on immunological assays. This simple, inexpensive and microchip-based platform presents a promising alternative to conventional
immunological assays for measurement of urinary albumin, and is well suited for clinical applications. 相似文献
10.
Chien LJ Wang JH Hsieh TM Chen PH Chen PJ Lee DS Luo CH Lee GB 《Biomedical microdevices》2009,11(2):359-367
A new micromachined circulating polymerase chain reaction (PCR) chip is reported in this study. A novel liquid transportation
mechanism utilizing a suction-type membrane and three microvalves were used to create a new microfluidic control module to
rapidly transport the DNA samples and PCR reagents around three bio-reactors operating at three different temperatures. When
operating at a membrane actuation frequency of 14.29 Hz and a pressure of 5 psi, the sample flow rate in the microfluidic
control module can be as high as 18 μL/s. In addition, an array-type microheater was adopted to improve the temperature uniformity
in the reaction chambers. Open-type reaction chambers were designed to facilitate temperature calibration. Experimental data
from infrared images showed that the percentage of area inside the reaction chamber with a thermal variation of less than
1°C was over 90% for a denaturing temperature of 94°C. Three array-type heaters and temperature sensors were integrated into
this new circulating PCR chip to modulate three specific operating temperatures for the denaturing, annealing, and extension
steps of a PCR process. With this approach, the cycle numbers and reaction times of the three separate reaction steps can
be individually adjusted. To verify the performance of this circulating PCR chip, a PCR process to amplify a detection gene
(150 base pairs) associated with the hepatitis C virus was performed. Experimental results showed that DNA samples with concentrations
ranging from 105 to 102copies/μL can be successfully amplified. Therefore, this new circulating PCR chip may provide a useful platform for genetic
identification and molecular diagnosis. 相似文献
11.
A microfluidic device combined with the microwell array and optical tweezers was set up for cell manipulation, localization
and cultivation. Yeast cells were manipulated by a 1,064 nm laser and transferred to microwell array as a demonstration. The
flow velocities at which the yeast cell can be confined in microwells of different sizes are charactered. The simulation of
the cell’s flow trace in the microwell at different flow velocities is consisting with our experiment result. And we also
proved a trapping laser power of 0.30 W is harmless for yeast cell cultivation. As a simple approach, this method can push
forward the cell cultivation, cell interaction and other cell biology or biomedical studies in microfluidic system. 相似文献
12.
Linder V Koster S Franks W Kraus T Verpoorte E Heer F Hierlemann A de Rooij NF 《Biomedical microdevices》2006,8(2):159-166
The study of individual cells and cellular networks can greatly benefit from the capabilities of microfabricated devices for
the stimulation and the recording of electrical cellular events. In this contribution, we describe the development of a device,
which combines capabilities for both electrical and pharmacological cell stimulation, and the subsequent recording of electrical
cellular activity. The device combines the unique advantages of integrated circuitry (CMOS technology) for signal processing
and microfluidics for drug delivery. Both techniques are ideally suited to study electrogenic mammalian cells, because feature
sizes are of the same order as the cell diameter, ∼ 50 μm. Despite these attractive features, we observe a size mismatch between
microfluidic devices, with bulky fluidic connections to the outside world, and highly miniaturized CMOS chips. To overcome
this problem, we developed a microfluidic flow cell that accommodates a small CMOS chip. We simulated the performances of
a flow cell based on a 3-D microfluidic system, and then fabricated the device to experimentally verify the nutrient delivery
and localized drug delivery performance. The flow-cell has a constant nutrient flow, and six drug inlets that can individually
deliver a drug to the cells. The experimental analysis of the nutrient and drug flow mass transfer properties in the flowcell
are in good agreement with our simulations. For an experimental proof-of-principle, we successfully delivered, in a spatially
resolved manner, a ‘drug’ to a culture of HL-1 cardiac myocytes. 相似文献
13.
Robert D. Lovchik Noemi Tonna Fabio Bianco Michela Matteoli Emmanuel Delamarche 《Biomedical microdevices》2010,12(2):275-282
We present a method for depositing cells in the microchambers of a sealed microfluidic device and establishing flow across
the chambers independently and serially. The device comprises a transparent poly(dimethylsiloxane) (PDMS) microfluidic network
(MFN) having 2 cell chambers with a volume of 0.49 μL, 6 microchannels for servicing the chambers, and 1 microchannel linking
both chambers. The MFN is sealed with a Si chip having 6 vias and ports that can be left open or connected to high-precision
pumps. Liquids are drawn through each chamber in parallel or sequentially at flow rates from 0.1 to 10 μL min−1. Plugs of liquid as small as 0.5 μL can be passed in one chamber within 5 s to 5 min. Plugs of liquid can also be introduced
into a chamber for residence times of up to 30 min. By injecting different liquids into 3 ports, 3 adjacent laminar streams
of liquid can be drawn inside one chamber with lateral concentration gradients between the streams ranging from 20 to 500
μm. The flexibility of this device for depositing cells and exposing them to liquids in parallel or serially is illustrated
by depositing two types of cells, murine N9 microglia and human SH-S5Y5 neuroblastoma. Microfluidic communication between
the chambers is illustrated by stimulating N9 microglia using ATP to induce these cells to release plasma membrane vesicles.
The vesicles are drawn through the second chamber containing neuroblastoma and collected in a port of the device for off-chip
analysis using confocal fluorescence microscopy. Cells in the MFN can also be fixed using a solution of formaldehyde for further
analysis after disassembly of the MFN and Si lid. This microfluidic device offers a simple, flexible, and powerful method
for depositing two cell populations in separate chambers and may help investigating pathways between the cells populations. 相似文献
14.
Cell characterization analysis usually involves a sequence of steps such as culture, separation, trapping, examination and
recollection. In general, it is difficult to recover the identified cells and achieve a multi-run examination on a single
chip for clinical samples. In the present study, a dielectrophoresis (DEP) micro-device was developed for multi-step manipulations
of cells at the single-cell level. The structure of the DEP chip consisted of an indium tin oxide (ITO) top electrode, a flow
chamber, a middle electrode on an SU-8 surface, a micro-cavity array of SU-8 and distributed electrodes at the bottom of the
micro-cavities. The purpose of the three-layer-electrode design was threefold. First, cells could be trapped into the micro-cavities
by negative DEP between the top and middle electrodes. After cells were trapped, cell analysis at the single-cell level could
potentially be performed. This could include, for example, drug treatment or biomedical sensing on the chip without applying
voltage. Once identified, the target cells could be individually released by controlling the bottom distributed electrodes.
Finally, the rest of the trapped cells could be pulled out by a positive DEP force between the top and middle electrodes and
flushed away for the next run of cell analysis. The multi-step manipulations of human bladder cancer cells (TSGH8301) were
successfully demonstrated and discussed, providing an excellent platform technology for a lab-on-a-chip (LOC). 相似文献
15.
Hideaki Tsutsui Edmond Yu Sabrina Marquina Bahram Valamehr Ieong Wong Hong Wu Chih-Ming Ho 《Annals of biomedical engineering》2010,38(12):3777-3788
In this study, we have developed an integrated microfluidic platform for actively patterning mammalian cells, where poly(ethylene
glycol) (PEG) hydrogels play two important roles as a non-fouling layer and a dielectric structure. The developed system has
an embedded array of PEG microwells fabricated on a planar indium tin oxide (ITO) electrode. Due to its dielectric properties,
the PEG microwells define electrical energy landscapes, effectively forming positive dielectrophoresis (DEP) traps in a low-conductivity
environment. Distribution of DEP forces on a model cell was first estimated by computationally solving quasi-electrostatic
Maxwell’s equations, followed by an experimental demonstration of cell and particle patterning without an external flow. Furthermore,
efficient patterning of mouse embryonic stem (mES) cells was successfully achieved in combination with an external flow. With
a seeding density of 107 cells/mL and a flow rate of 3 μL/min, trapping of cells in the microwells was completed in tens of seconds after initiation of the DEP operation. Captured
cells subsequently formed viable and homogeneous monolayer patterns. This simple approach could provide an efficient strategy
for fabricating various cell microarrays for applications such as cell-based biosensors, drug discovery, and cell microenvironment
studies. 相似文献
16.
We present the development of a three-dimensional (3-D) combinatorial cell culture array device featured with integrated three-input,
eight-output combinatorial mixer and cell culture chambers. The device is designed for cell-based screening of multiple compounds
simultaneously on a microfluidic platform. The final assembled device is composed of a porous membrane integrated in between
a Parylene 3-D microfluidic chip and a PDMS microfluidic chip. The membrane turned the cell culture chambers into two-level
configuration to facilitate cell loading and to maintain cells in a diffusion dominated space during device operation. Experimentally,
we first characterized the combined compound concentration profile at each chamber using a fluorescence method. We then successfully
demonstrated the functionality of the quantitative cell-based assay by culturing B35 rat neuronal cells on this device and
screening the ability of three compounds (1,5-dihydroxyisoquinoline, deferoxamine, and 3-aminobenzoic acid) to attenuate cell
death caused by cytotoxic hydrogen peroxide. In another experiment, we assayed for the combinatorial effects of three chemotherapeutic
compound exposures (vinorelbine, paclitaxel, and γ-linolenic acid) on human breast cancer cells, MDA-MB-231. The same technology
will enable the construction of inexpensive lab-on-a-chip devices with high-input combinatorial mixer for performing high-throughput
cell-based assay and highly parallel and combinatorial chemical or biochemical reactions. 相似文献
17.
Human mesenchymal stem cells (MSCs) have the potential to differentiate into multiple tissue lineages for cell therapy and,
therefore, have attracted considerable interest recently. In this study, a new microfluidic system is presented which can
culture and differentiate MSCs in situ. It is composed of several components, including stem cell culture areas, micropumps, microgates, seeding reservoirs, waste
reservoirs and fluid microchannels; all fabricated by using micro-electro-mechanical-systems (MEMS) technology. The developed
automated system allows for the long-term culture and differentiation of MSCs. Three methods, including Oil Red O staining
for adipogenic cells, alkaline phosphatase staining and immunofluorescence staining are used to assess the differentiation
of MSCs. Experimental results clearly demonstrate that the MSCs can be cultured for proliferation and different types of differentiation
are possible in this microfluidic system, which can maintain a suitable and stable pH value over long time periods. This prototype
microfluidic system has great potential as a powerful tool for future MSC studies. 相似文献
18.
This study reports a new microfluidic system integrated with a microfluidic control module and a micro electrochemical module
for detection of urinary proteins. The integrated microsystem can automatically detect proteins in urine with a high sensitivity.
The microfluidic control module consists of a new two-way, spiral-shape micropump which can transport the urine samples to
the sensing regions. The net ionic charges of the protein samples can be detected while the samples flow through the sensing
region of the micro electrochemical module. Two major urinary proteins including lysozyme and albumin are detected in a multiple-channel
layout with little human intervention and are analyzed in a short period of time, while only consuming a 100-μl urine sample.
The developed microfluidic system could lead to a convenient, yet crucial, platform for chemical and biological detection
and diagnosis.
Preliminary results of the current paper had been presented at the 1st Annual IEEE International Conference on Nano/Molecular
Medicine and Engineering, August 6–9, 2007. 相似文献
19.
Song-I Han Ki-Ho Han A. Bruno Frazier Jerome P. Ferrance James P. Landers 《Biomedical microdevices》2009,11(4):935-942
This paper presents an automated micro-SPE device for DNA extraction using monolithically integrated high-pressure microvalves.
The automated micro-SPE device was fabricated through glass-to-glass thermal bonding and microfluidic system interface technologies.
To increase the DNA extraction efficiency, silica beads were packed in the extraction microchannel involving two weir structures.
Experimental results show that the DNA extraction efficiency using the automated micro-SPE device containing bare silica beads
was 75.87% in the first 8 μl of solution eluted by automated SPE procedure. In addition, the reproducibility of the DNA extraction
was evaluated by ten successive measurements. Genomic DNA extracted from human WBCs had an absorbance ratio of DNA to protein
(A260/A280) of 1.56. The applicability of this automated micro-SPE device to genetic sample preparation was verified by PCR amplification
of a β-globulin gene using the genomic DNA extracted from WBCs. Consequently, we demonstrated that the proposed automatic
micro-SPE device can extract nucleic acids from biological samples, thereby facilitating its integration with downstream genetic
analyses in a micro format. 相似文献
20.
Giovanni De Gasperis Jun Yang Frederick F. Becker Peter R. C. Gascoyne Xiao-Bo Wang 《Biomedical microdevices》1999,2(1):41-49
We describe a microfluidic device for separating cells according to their dielectric properties by combining 2-dimensional dielectrophoretic forces with field-flow-fractionation. The device comprises a thin chamber in which a travelling-wave electrical field is generated by a planar, multilayer microelectrode array at the bottom. Under the balance of gravitational and dielectrophoretic levitation forces, cells introduced into the device are positioned at different equilibrium heights in a velocity profile established inside the chamber, and thereby transported at different velocities by the fluid. Simultaneously, cells are subjected to a horizontal travelling-wave dielectrophoretic force that deflects them across the flow stream. The 2-dimensional dielectrophoretic forces acting on cells and the associated velocities in the fluid-flow and travelling-field directions depend sensitively on cell dielectric properties. The responses of cultured MDA-435 human breast cancer, HL-60 human leukemia and DS19 murine erythroleukemia cells, and of peripheral blood mononuclear (PBMN) cells were studied as functions of the frequency and voltage of the applied electric signals, and of the fluid flow rate. Significant differences were observed between the responses of different cell types. Cell separation was demonstrated by the differential redistribution of MDA-435 and PBMN cells as they flowed through the device. The device can be readily integrated with other microfluidic components for microscale sample preparation and analysis. 相似文献