Papers by Maria Agirregabiria
RSC Advances, 2015
This paper describes a bead beating-based miniaturized cell lysis device that works in continuous... more This paper describes a bead beating-based miniaturized cell lysis device that works in continuous flow allowing the analysis of large volumes of samples without previous treatment.
We present a hand held system consisting of a portable platform and disposable Labcard capable of... more We present a hand held system consisting of a portable platform and disposable Labcard capable of performing a nucleic acid concentration, amplification and detection (Figure 1). The Labcard comprises two inlets, two outlets, five microvalves, and two chambers (a concentration chamber and an amplification chamber with stored reagents) ( Figure 2). It is made of a Cyclo Olefin Copolymer (COC) substrate sealed by a polypropylene film coated with a pressure sensitive adhesive. The assay is carried out in a sequential manner and automatically controlled by a laptop. First, magnetic bead-based concentration, washing and elution are carried out in the first chamber. Then, the eluted DNA is transferred to the second chamber where the stored reagents are rehydrated. Finally, a quantitative Polymerase Chain Reaction (qPCR) takes place in the second chamber. The fluorescence created during the qPCR is recorded in real time by the platform. The use of the magnetic bead protocol allows the Labc...
L'invention concerne un procede de fabrication de dispositifs microfluidiques composes d'... more L'invention concerne un procede de fabrication de dispositifs microfluidiques composes d'une feuille (1) d'epaisseur egale ou inferieure a 200 micrometres et d'une piece rigide (3) toutes deux en matiere polymere thermoplastique qui comprend: - le degazage: -d'une feuille polymere de matiere thermoplastique (1) - d'une piece auxiliaire rigide (2) - d'une feuille polymere de matiere thermoplastique (3) - le collage par un procede de collage temporaire, de la feuille polymere thermoplastique (1) degazee, sur une piece auxiliaire rigide (2) degazee donnant lieu a un ensemble feuille-piece piece auxiliaire (4), - collage par collage permanent, de la feuille polymere thermoplastique (1) de l'ensemble feuille-piece auxiliaire (4) obtenu lors de l'etape de collage temporaire anterieur, sur la piece rigide polymere thermoplastique (3) degazee initialement, - decollement de la piece auxiliaire rigide (2) de la feuille polymere thermoplastique (1) collee de...
In this study, we describe a simple and efficient method for on-chip storage of reagents for poin... more In this study, we describe a simple and efficient method for on-chip storage of reagents for point-of-care (POC) diagnostics. The method is based on gelification of all reagents required for on-chip PCR-based diagnostics as a ready-to-use product. The result reported here is a key step towards the development of a ready and easy to use fully integrated Lab-on-achip (LOC) system for fast, cost-effective and efficient POC diagnostics analysis.
This work describes a SU-8 microdevice for the detection of Salmonella spp. This device is capabl... more This work describes a SU-8 microdevice for the detection of Salmonella spp. This device is capable of: (i) concentrating the target microorganisms from human faecal samples, (ii) lysing them and (iii) amplifying the extracted DNA by real time Polymerase Chain Reaction (q-PCR). All the steps are carried out in a single 1.5 mul microchamber in 25 minutes. Unlike previous reported PCR devices, this work describes a membrane valve compatible with the PCR chamber.
Procedia Engineering, 2012
This paper presents a self contained system consisting of a portable platform and a disposable La... more This paper presents a self contained system consisting of a portable platform and a disposable LabCard capable of performing a nucleic acid concentration, amplification, and detection. The LabCard comprises several inlets and outlets, integrated microvalves, two chambers and stored reagents. In the first chamber it is performed a magnetic beads-based DNA concentration, washing and elution. Then, the eluted DNA is transferred to the second chamber where it rehydrates with the pre-stored reagents. Finally, a real-time Polymerase Chain Reaction (qPCR) takes place and the fluorescence signal is recorded and displayed in real time. The magnetic bead protocol allows the LabCard to process a wide range of sample volumes (from 10 μl to 10 ml). The PCR reagents are stored inside the LabCard using a gelification technique allowing: (i) long-term storage of the LabCards, (ii) reduction of the reagent volumes, and (iii) significant simplification of the LabCard design and user operation. The cross contamination is avoided by making the LabCard disposable. On the other hand, the platform has been conceived as a comprehensive and generic solution able to perform a wide range of biological assays. These assays consist in an automated and programmable sequence of sample preparation phases followed by a DNA amplification and detection phase.
Lab on a Chip, 2009
We present a lensfree digital microscopy platform implemented on a cell-phone. It operates based ... more We present a lensfree digital microscopy platform implemented on a cell-phone. It operates based on digital in-line holography and provides a compact and lightweight alternative to conventional microscopes, such that the cell-phone is modified with an inexpensive attachment weighing only ~38 grams. This lensfree cell-phone microscope captures holographic images of the objects which are then rapidly processed by a custom-developed reconstruction algorithm to provide microscopic images of the sample. This mechanically-robust cellphone microscope achieves a numerical aperture of ~0.1-0.2 over an imaging field-of-view (FOV) of ~24 mm 2 and may provide a cost-effective and field-portable diagnostics tool for telemedicine applications.
Journal of Micromechanics and Microengineering, 2004
... Page 3. FJ Blanco et al pumps have been fabricated [5]. The integration of PDMS 3D microfluid... more ... Page 3. FJ Blanco et al pumps have been fabricated [5]. The integration of PDMS 3D microfluidicdevices with CMOS electronics or Si-based MEMS devices is nontrivial. ... Due to the simple andlow cost fabrication, SU-8 has been employed to fabricate passive components of ...
Journal of Micromechanics and Microengineering, 2007
This work describes the fabrication and characterization of a complete polymeric microfluidic dev... more This work describes the fabrication and characterization of a complete polymeric microfluidic device monolithically integrated within metallic electrodes. The fabrication is performed by using standard photolithography, metal deposition and wafer bonding onto polymer substrates, which dramatically reduces the final cost and allows repeatable volume production with respect to the current technology. The negative epoxy photoresist SU-8 has been employed to
rsc.org
This paper reports on a novel two-chamber SU8 LabonaChip (LoC) for sample concentration, purifica... more This paper reports on a novel two-chamber SU8 LabonaChip (LoC) for sample concentration, purification and Polymerase Chain Reaction (PCR). This typical sequence of reactions demands highly integrated microfluidic control. The burst valve concept presented in this work aims at addressing this problem, providing an integrated solution based on the controlled rupture of a vertical SU-8 wall. Owing to its vertical construction, the valve can be readily integrated into any geometry with low increase in footprint. A valve regulated double-chamber device for DNA concentration has been successfully fabricated and a full DNA concentration, elution and transportation protocol has been carried out.
ABSTRACT A new method for aliquoting samples in different reaction chambers is reported in this a... more ABSTRACT A new method for aliquoting samples in different reaction chambers is reported in this abstract. It is useful for aliquoting and running multiple simultaneous nucleic acid-based reactions and spatial multiplexes originated from an individual sample
This work describes a SU-8 microdevice for the detection of Salmonella spp. The chip is able to p... more This work describes a SU-8 microdevice for the detection of Salmonella spp. The chip is able to perform all the required steps: concentration of the target microorganisms from human faecal samples, their lyse and the amplification of the extracted DNA by real time-PCR (qPCR), all in a single microchamber. PCR devices made of SU-8 have been reported before . However this is the first time that sample preparation and q-PCR have been performed using a SU-8 chamber. Several improvements were achieved in comparison with other q-PCR devices made of silicon or PDMS [6, 7]: (i) real human samples were used; (ii) microorganisms concentration, lysis and qPCR were carried out in a single microchamber; (iii) less PCR mixture (2.5 µl) was required; (iv) less time (25 minutes) was needed for the complete analysis and (v) a higher sensibility (C T =15) was obtained. The SU-8 fabrication process reported on [8] was adapted to obtain the devices, which design and picture of the typical result are shown in respectively. These devices were based on 200 µm high, 3 mm wide and 5.4 mm long microchamber (2.5 µl), fabricated on a Pyrex substrate, where a resistive Ti/Pt sensor and two parallel heaters were previously fabricated by sputtering and lift off. This fabrication process , based on the bonding and releasing of photopatterned SU-8 layers, allowed a considerable time and money reduction in comparison with silicon based devices . In addition, the SU-8 photolithography offered more precise dimensional tolerances and easier electrode integration than replicated PDMS . Finally, in contrast with other SU-8 related works [1, 3], the sealing layer was also developed, simplifying the packaging. The experimental procedure described in was carried out to characterise the devices. Analyzed stool samples were previously diagnosed as salmonellosis by q-PCR at laboratory scale. A swab was then inserted in a stool sample, transferred to sterile buffer and left to release the bacteria. Next, resuspended magnetic beads anti Salmonella were added. Sample containing beads was inserted in the packaged SU-8 microdevice using a syringe. The magnetic field created by magnets placed under and above the device captured the beads and complex beads-bacteria while the liquid was displaced (see ). Subsequently, PCR mastermix was inserted, the inlet/outlet were sealed, magnets were carried off and lysis and amplification were performed. The initial 10 min-denaturation step at 94ºC was enough for cell thermal lysis. shows the result of this experimental procedure. The whole protocol, including Salmonella spp. concentration, DNA extraction and Real Time amplification was achieved in 25 minutes. The Cy5 fluorescence signal was observed in real time by the photomultiplier tube through the SU-8 cover. The real time method showed a high specificity and accuracy. This work proves that a simple syringe, a SU-8 microdevice and a photomultiplier are enough to carry out a complete analysis for Salmonella spp. detection in faeces, from real human sample preparation to rapid pathogen identification.
Frontiers in Materials, 2015
Tissues are complex three-dimensional structures in which cell behavior is frequently guided by c... more Tissues are complex three-dimensional structures in which cell behavior is frequently guided by chemotactic signals. Although starvation and nutrient restriction induce many different chemotactic processes, the recreation of such conditions in vitro remains difficult when using standard cell culture equipment. Recently, microfluidic techniques have arisen as powerful tools to mimic such physiological conditions. In this context, microfluidic three-dimensional cell culture systems require precise control of cell/hydrogel location because samples need to be placed within a microchamber without obstruction of surrounding elements. In this article, SU-8 is studied as structural material for the fabrication of complex cell culture microdevices due to its good mechanical properties and sensor integration capacity. Moreover, SU-8 physical properties and their effect on a successful design for precise control of hydrogel location within microfluidic devices are studied. In particular, this manuscript presents a SU-8 based microdevice designed to create "self-induced" medium starvation, based on the combination of nutrient restriction and natural cell metabolism. Results show a natural migratory response toward nutrient source, showing how cells adapt to their own microenvironment modifications. The presented results demonstrate the SU-8 potential for microdevice fabrication applied to cell culture.
The use of flexible polymers as substrate materials offers a rapid and economical production of m... more The use of flexible polymers as substrate materials offers a rapid and economical production of microfluidic devices (1). Furthermore, a polymer based system provides flexibility to the final product, which can be very beneficial for certain application, such as in vivo drug delivery devices (2). In this paper the fabrication of microfluidic devices made only of SU8 polymer with integrated
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Papers by Maria Agirregabiria