Methods and apparatus for the selection and/or processing of particles, in particular for the selective and/or optimised lysis of cells

Abstract

Methods and apparatus for the selection or processing of particles sensitive to the application of an external stimulus to rupture/lysis at least one selected particle or the fusion of first and second selected particles are disclosed herein. Particles are organized using a first field of force by selectively energizing electrodes of an array of selectable electrodes having dimensions comparable to or smaller than those of the particles. A first configuration of stresses is applied to the electrodes; and then a second configuration of stresses is applied to the electrodes, so as to create a second field of force, located substantially close to at least one selected particle to be lysated or to a pair of first and second particles to be fused and such as to produce the application of a stimulus suited to produce their lysis or fusion.

Claims

1. An apparatus for the selection and processing of particles that are micrometric or nanometric entities, comprising: at least one first microchamber configured to contain in use a fluid carrying said particles suspended therein and provided with an array of selectable and addressable electrodes having dimensions substantially comparable to or smaller than those of said particles, said array of selectable electrodes being configured to generate a first field of force in response to application to said array of electrodes of a first pattern of voltages; a plurality of second microchambers, each second microchamber having dimensions comparable to but larger than those of said particles, each second microchamber comprising at least one electrode configured to be selectively activated and selected to generate a second field of force located substantially close to said at least one electrode of each second microchamber, in response to application to said at least one electrode of each second microchamber of a second pattern of voltages; and a plurality of channels, each channel being a different one of the plurality of second microchambers each said second microchamber to said at least one first microchamber, wherein: each said second microchamber constitutes a point of analysis of micrometric dimensions for a defined analysis protocol, said array of electrodes is configured to shift said particles, selectively, each into one of the said second microchamber, through a respective one of the plurality of channels, said at least one electrode of the each second microchamber is configured to carry out a lysis of each said particle present in use in said point of analysis of micrometer dimensions, each said second microchamber being further configured to apply said defined analysis protocol to debris of a lysis of said particles present in use in said point of analysis of micrometer dimensions, and each of said plurality of channels has a length and/or shape such as to prevent or at least substantially slow down any diffusive phenomenon between said at least one first microchamber and said second microchambers and among said second microchambers themselves for a time necessary to carry out said defined analysis protocol.

2. The apparatus according to claim 1, wherein at least a portion of said plurality of second microchambers are connected to a channel for capillary electrophoresis.

3. The apparatus according to claim 2, wherein said portion of said plurality of second microchambers are connected to the channel for capillary electrophoresis by a cross junction.

4. The apparatus according to claim 2, wherein at the end of said channel for capillary electrophoresis there is at least one optical or impedenziometric sensor.

5. The apparatus according to claim 1, wherein at least a portion of said plurality of second microchambers is connected to a capillary for electrophoresis through respective fluid outlets of each one of the portion of said plurality of second microchambers.

6. An apparatus for selecting and processing particles, comprising: a first microchamber comprising an array of selectable and addressable first electrodes, wherein each first electrode has dimensions on the order of micrometers, and the array of first electrodes is configured to generate a first field of force in response to application to the array of first electrodes a first pattern of voltages; a plurality of second microchambers, wherein each second microchamber has dimensions comparable to but larger than the first electrodes, each second microchamber comprises at least one second electrode that is configured to be selectively activated to generate a second field of force located substantially close to the at least one second electrode in response to application of a second pattern of voltages to the at least one second electrode; and a plurality of channels hydraulically connecting the first microchamber to the plurality of second microchambers, each channel of the plurality of channels hydraulically connecting the first microchamber to a different one of the plurality of second microchambers, wherein: the array of first electrodes is configured to selectively shift a particle contained in the first microchamber through a respective one of the plurality of channels into the hydraulically second microchamber, the second field of force is configured to lyse the particle present in the second microchamber, each second microchamber is configured to be a point of analysis for a defined analysis protocol and perform the defined analysis to debris of the lysed particle, and each of the plurality of channels has a length and/or shape to prevent or substantially slow down diffusive phenomenon of the debris of the lysed particle between the hydraulically connected first and second microchambers and among the plurality of second microchambers for a time sufficient to perform a defined analysis protocol.

7. The apparatus of claim 6, further comprising a channel for capillary electrophoresis connected to at least a portion of the plurality of second microchambers.

8. The apparatus of claim 7, wherein the at least a portion of the plurality of second microchambers are connected to the channel for capillary electrophoresis by a cross junction.

9. The apparatus of claim 7, further comprising at least one optical or impedenziometric sensor disposed at an end of the channel for capillary electrophoresis.

10. The apparatus of claim 6, wherein at least a portion of the plurality of second microchambers comprises a fluid outlet connected to a capillary for electrophoresis.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 schematically illustrates the steps of a first method according to the invention carried out in a manipulation apparatus illustrated in section in elevation;

(2) FIG. 2 illustrates the steps of the method in FIG. 1 carried out with the same apparatus as in FIG. 1, but illustrated in layout viewed from above;

(3) FIG. 3 illustrates in the same view as FIG. 2 a possible variation of the method in FIGS. 1 and 2;

(4) FIG. 4 illustrates the actuation of the method in FIG. 1 with a photographic sequence;

(5) FIG. 5 illustrates in the same view as FIG. 2 a further variation of the method in FIG. 1;

(6) FIG. 6 illustrates in the same view as FIG. 2 a further method of the manipulation of particles according to the present invention; and

(7) FIGS. 7 to 9 illustrate different embodiments of an apparatus for a particularly advantageous actuation of the methods of the invention.

DETAILED DESCRIPTION

(8) The aim of the present invention is to carry out methods and apparatus for the manipulation and/or separation and/or analysis of particles.

(9) The methods of the invention are based (FIG. 1) on the use of a non uniform field of force (F) with which to attract single particles or groups of particles (CELL) towards positions of stable equilibrium (CAGE). This field may be, for example, a field of dielectrophoresis (DEP), negative (NDEP) or positive (PDEDP), or a field of electrohydrodynamic movements (EHD).

(10) The processing carried out on the cells is based on the application of localised electric fields able to provoke the permanent rupture of the cellular membrane, or the fusion of two particles.

(11) The method may also make use of integrated sensors, preferably of the optical and/or impedenziometric type, for example in all those steps in which it is necessary to check the type of particles close to certain electrodes. Alternatively, similar information may be available by means of non integrated optical sensors, coupled to a microscope, which allows the examination of the contents of the microchamber in which the methods of the invention are being carried out.

(12) Generation of Forces

(13) There are various methods for generating forces to shift particles, according to the prior art, by means of arrays of electrodes (EL), formed on a substratum. Typically, according to previous patents of the same Applicant (FIG. 1), a cover (LID) is used, which may in turn be an electrode, which delimits a microchamber, in which are the particles (CELL), typically suspended in a fluid composed of a liquid. In the case of dielectrophoresis (DEP), the voltages applied are periodic in-phase voltages (Vphip) indicated with the plus sign (+) and counterphase voltages (Vphin) indicated with the minus sign (−). The term “counterphase voltages” means voltages offset by 180°. The field generates a force which acts on the particles of a region of space (CAGE), attracting them towards a point of equilibrium (PEQ). In the case of negative DEP (NDEP), it is possible to produce closed force cages, according to the prior art, if the cover (LID) is a conductive electrode; in this case the point of equilibrium (MPEQ) corresponds to each electrode connected to Vphin (−) if the adjacent electrodes are connected to the opposite phase Vphip (+) and if the cover (LID) is connected to the phase Vphin (−). This point of equilibrium (MPEQ) is normally at a distance in the liquid with respect to the electrodes, so the particles (CELL) are in levitation, in a stationary state.

(14) In the case of positive DEP (PDEP) the point of equilibrium (ZPEQ) is normally at the surface on which the electrodes are realised, and the particles (CELL) are in contact with it, in a stationary state. For the PDEP it is not necessary to have further electrodes in the cover, because the points of equilibrium of the PDEP correspond to the maximums of the electric field. For the electro-hydrodynamic movements (EHD), the configurations of electrodes generate flows which push the particles towards the minimum points of the flow.

(15) For the sake of simplicity, below is considered purely as an example, and therefore without limitation for the purposes of the present invention, the use of closed cages with negative dielectrophoresis as the activating force for the steps of particle movement in the description of the methods and apparatus (for which it is necessary to use a cover acting as an electrode) of the invention. To experts of the sector with ordinary abilities it is clear that it is possible to generalise the methods and apparatus described below for the use of different activating forces, and different types of particles.

(16) Method for the Selective Lysis of Particles

(17) The particles to be lysated are positioned close to the gap between two electrodes by one of the above mentioned actuation forces, energising the electrodes with sinusoidal voltages of a first amplitude (MA) and frequency (MF). The gap is preferably smaller than 10 μm, and typically around 1-3 μm, so that a low voltage stimulus, compatible with the supply voltage of an integrated circuit (e.g. 2.5, 3.3 or 5 V), is enough to determine a transmembrane potential sufficient to cause the irreversible rupture of the particle.

(18) This stimulus is preferably composed of a train of sinusoidal impulses of a second amplitude (ZA) and a second frequency (ZF).

(19) Electric impulses are applied between the two selected electrodes so as to provoke the lysis of the cell.

(20) FIG. 1 shows in section the evolution over time of the fields of force and of the “patterns” (that is the complex of configurations of (+) or (−) state of the electrodes) of the voltages applied to the electrodes, according to a preferential embodiment of the invention. In FIG. 1(a), the cells (CELL) are in nDEP, suspended in the liquid in a first point of equilibrium (MPEQ). In FIG. 1(b) the pattern of voltages applied to the electrodes (EL) changes, so the frequency and optionally the amplitude of the voltages applied, as well as the force to which the cells are subjected, change to pDEP (FZAP). However, thanks to the change of the pattern of voltages, only the cell to be lysated (CELLZ) is subjected to a significant force, so it is attracted towards a new point of stable equilibrium (ZPEQ). Near that point the electric field is maximum and the frequency is such that a sufficient transmembrane potential to lysate the cell is provoked.

(21) FIG. 2 shows in layout the configurations of electrodes for the same steps (a)-(d) as FIG. 1, where the pattern of electrodes in phase and counterphase with the voltage applied to the lid is indicated by the colour (in phase grey, in counterphase white).

(22) This sequence of patterns is particularly favourable since, during lysis, the other cells in neighbouring areas are subjected to an almost null electric field, as both the cover and the electrodes are in phase. If the amplitude of the voltage applied to the cover is equal to the amplitude of the voltage applied to the electrodes, the field on those cells is null.

(23) Alternatively, the series of patterns shown in FIG. 3(a)-3(d) may be adopted. In this case, as is shown by the number of electrodes in phase and counterphase represented by the colours white and grey, the advantage lies in the need to reprogramme a smaller number of electrodes each time, which may be advantageous if the process of writing the memory cells for the pattern of electrodes to be actuated is slow. Otherwise it is generally preferable to adopt the previous solution in FIG. 2.

(24) With sensors integrated in the array of electrodes that delimit the bottom surface of the microchamber, for example of optical type, it is easy to check when lysis has occurred, using the methods described in the above-mentioned international patent application no. PCT IB 2006000636 of the same Applicant, to see whether the cage corresponding to the lysated cell is still full or empty, or better to check for the presence of debris resulting from lysis.

(25) Substantially, with the methods described it is possible to select or process particles sensitive to the application of an external stimulus using a method comprising in general the step of producing, by applying said external stimulus, the rupture or lysis of at least one selected particle; and wherein are also contemplated the steps of:

(26) a) bringing the particles (CELL) close to electrodes (EL) of an array of selectable electrodes having dimensions comparable to or smaller than those of said particles, to which may be applied a first pattern (PMAN) of tensions to organise optionally, if necessary, said particles (CELL) by means of a first field of force (FMAN), by selectively energising said electrodes (EL);

(27) b) applying to the electrodes a second pattern (PZAP) of voltages, so as to create a second field of force (FZAP), located substantially close to at least one selected particle to be lysated (CELL) and such as to produce the application to said at least one selected particle of a stimulus suited to produce its rupture or lysis.

(28) The particles are suspended in a chosen fluid, in case one wants to use the passage from nDEP to pDEP as described previously to obtain lysis, so as to present a relatively low electric conductivity.

(29) The first pattern (PMAN) of voltages for generating the first field of force (FMAN) presents a first amplitude (MA) and a first frequency (MF); and the second pattern (PZAP) of voltages for generating the second field of force (FZAP) presents a second amplitude (ZA) and a second frequency (ZF), at least one of which is different from said first amplitude (MA) and first frequency (MF). In this case, the stimulus applied to obtain lysis consists of a force that can be applied to the at least one selected particle by the second field of force (FZAP) and both the first and the second pattern of voltages are generated in AC (alternating current). In particular, the at least one selected particle is a biological entity with a lysable membrane, in the examples described a cell, and the stimulus applied consists of bringing the transmembrane potential of the at least one selected particle to a value such as to produce the rupture of the membrane.

(30) According to a possible variation of the method of the invention, which may be considered illustrated in FIG. 2(b), the stimulus applied to the selected particle to lysate it consists vice versa of heating located in the fluid in which is suspended the selected particle to be lysated.

(31) According to this possible variation, particularly advantageous if the particles are suspended in a fluid (liquid) presenting a high electric conductivity (for example physiological solution), the second pattern (PZAP) of voltages is such as to produce the selective heating by Joule effect of those selected electrodes in the array of electrodes with which the second field of force (FZAP) is generated, in FIG. 2(b) the electrode shown in white, on which the whole current supplied to the device illustrated is practically concentrated.

(32) In this case it is clear that at least the second pattern of voltages may be generated in either AC or DC (direct current).

(33) Anyway, the methods described according to the invention include a step of checking the lysis of the at least one selected particle, preferably carried out by means of the already mentioned sensors integrated with the array of electrodes, in a single chip.

(34) Lastly, according to a further possible variation of the methods described, if one is interested in selectively recovering the debris produced by lysis, after the step b) described above, the following steps may be carried out:

(35) c) applying said first pattern (PMAN) of voltages to the electrodes again; and

(36) d) while step c) is in progress, producing a slow and controlled shift of the fluid to recover a selected product of lysis of the at least one selected particle.

(37) In fact, as is well known to experts in the field, in the case of actuating the movement of the particles by dielectrophoresis, the forces acting on the particles due to the applied field are in proportion to the cube of the radius of the particles, while the forces of hydrodynamic viscous friction are in proportion only to the radius of the particles; therefore the smallest particles (the debris of lysis in this specific case) may be carried along by a moderate flushing of the fluid in which the particles are suspended, while the largest particles (the non lysated cells) are kept in a stationary position (against the viscous flushing action) by the nDEP cages positioned in stationary mode and in which the cells are trapped.

(38) The efficacy of the methods described, in particular of the method according to the FIGS. 1 and 2, is shown in FIG. 4. Two Raji cells suspended in an aqueous solution with Mannitol 280 mM (millimolar) and KCl 6.25 mM are organised, see FIG. 4(a), by the electric field (MF) applied (MA) in which the electrodes in the array have sinusoids with a peak-peak amplitude of 3.3 V, the conductive cover (LID) an amplitude of 6.6V, all with frequency 50 kHz. The cells are taken onto the in-phase electrodes with the lid surrounded by electrodes of the opposite phase (offset by 180°.

(39) After that, the pattern of the voltages applied to the electrodes varies, putting into counterphase also the electrode on the cell at bottom right, which must be preserved. Although there is no cage, the cell remains in the same position, due to inertia. Instantaneously, the applied electric field changes so as to produce positive dielectrophoresis (FZAP), bringing the frequency of the electric field (ZF) to 400 kHz, and the particle still present in the cage (CELLZ) goes into a new point of stable equilibrium due to the force of positive dielectrophoresis, now generated by the field, which is on the gap between the electrodes, see FIG. 4(b). That region corresponds to the maximums of the electric field, which at that frequency are sufficient to provoke the lysis of the membrane, see FIG. 4(c).

(40) It appears clear to experts in the sector with ordinary abilities that the electric field may be varied, in different ways, in particular also (or only) in amplitude, or the initial pattern of electrodes for manipulation and lysis may be chosen differently, for example as in FIG. 5.

(41) In this case, it starts from a nDEP pattern, FIG. 5(a), which positions the particles in a point of equilibrium (MPEQ) lying vertically to the point of equilibrium for the pDEP (ZPEQ), for the next pattern of electrodes. In this way the selected cell does not move from its vertical line, and the lysis process can be accelerated because the cell takes less time to reach the area of maximum electric field in which lysis takes place.

(42) Method for Particle Fusion Assisted by Dielectrophoretic Manipulation

(43) In this case, two particles are brought into contact in the same point of stable equilibrium (MPEQ) by the force (F) generated by the electrodes (EL). The stimulus that is applied next to the pair of cells in contact is chosen with an amplitude and frequency such as to provoke a fusion of the two cellular membranes into a single entity (FIG. 6).

(44) With sensors integrated in the chip that holds the array of electrodes, for example of an optical type, it is then possible to check that fusion has taken place without the need of an external microscope.

(45) Applications of fusion include for example the generation of hybrids, of both eucariot cells and bacteria, or of plants.

(46) For example, one could consider the possibility of using a similar method to reprogramme differentiated cells towards stem cells, for example combining a differentiated cell with an enucleated stem cell.

(47) So, according to this method, the fusion of first particles with second particles is produced, in which the first and second particles are biological entities with a lysable membrane, for example cells or micro-organisms, and in which the membrane of the particles is sensitive to the application of an external stimulus, performing the steps of:

(48) a) bringing said first and second particles (CELL) close to electrodes (EL) of an array of selectable electrodes having dimensions comparable to or smaller than those of said particles, to which may be applied a first pattern (PMAN) of tensions to organise optionally, if necessary, said first and second particles (CELL) by means of a first field of force (FMAN), by selectively energising said electrodes (EL);

(49) b) applying to the electrodes a second pattern (PZAP) of voltages, so as to create a second field of force (FZAP), located substantially close to at least one first and one second selected particles to be fused together and such as to produce the application to the same of a stimulus suited to produce the fusion of the membranes of the first and second selected particles.

(50) Method of Isolating Cells By Survival

(51) A multiplicity of cells is flushed in suspension in the microchamber with the array of electrodes. Using integrated sensors (for example optical and/or impedenziometric) and/or external sensors (for example an optical sensor coupled to a microscope, with or without fluorescence), the type or cell found in each point of equilibrium (PEQ) is identified. Stimuli for lysis are then applied selectively to all the cells that are not interesting, preserving the vitality of the neighbouring interesting cells.

(52) The sample is then flushed out, recovering the interesting live cells and the lysate of non interesting cells.

(53) According to the description, a method is therefore carried out for isolating interesting particles from a population of particles including the interesting particles, characterised in that it comprises the following steps:

(54) a) introducing the population of particles, suspended in a fluid, into a microchamber, where the microchamber is provided with an array of selectable electrodes;

(55) b) applying to said population of particles the method of selective lysis described above to produce the selective lysis of all the particles of the population except the interesting ones;

(56) c) recovering the interesting particles.

(57) Step b), particularly in the case where the position of the interesting particles with respect to the array of electrodes is not known a priori and the interesting particles possess characteristics such as to be sensitive only to a determined intensity and/or type of stimulus (also not known a priori), is applied simultaneously and/or repeatedly to all the particles of the particle population by applying to said electrodes a plurality of voltage patterns suited to apply to said particles stimuli of an intensity and/or type such as to produce, in this way, the selective lysis of all the particles in the particle population except the interesting ones.

(58) The different type may for example include the application of AC voltages with determined frequencies, known to be ineffective in the lysis of the interesting particles, but to be efficacious for the lysis of the remaining particles. The different intensity may for example be a growing intensity.

(59) With respect to isolation based on moving the interesting cells into a second microchamber for recovery, the method described above presents the following advantages:

(60) 1. Speed of Execution

(61) The cells move slowly under the described forces (DEP, ETF, EHD) of actuation, and the sorting based on moving the cells into a microchamber for recovery is therefore relatively slow. Vice versa, the time to complete the sorting operation based on survival requires only one cell to have reached the nearest point of stable equilibrium (PEQ), and the time of lysis of the cell (about one second), and it is not necessary to move it through the whole selection microchamber.

(62) 2. A Cooling System is not Necessary

(63) The cells to be eliminated can be lysated in series, working by sub-regions of the microchamber. In this way it is not necessary to have cooling systems, even for working on very large chips with relatively conductive buffers, because the quantity of heat developed is proportional to the energised area, which may be made as small as one likes.

(64) 3. The Chip May have Very Large Dimensions

(65) As it is not necessary to energise the whole chip at the same time, the problem of resistive drop on the tracks that carry the stimuli to the various electrodes is correspondingly reduced. Above all with relatively conductive buffers, and with low pitch between electrodes, the resistive drop on the tracks inside the chip and/or the drop on the conductive layer of the lid (when NDEP cages are used for actuation) is not negligible if the whole array of electrodes is energised. Energising only a part of the layer, the resistive load to be managed is limited and the voltage drop on the tracks is decreased.

(66) 4. Operation Also with Cells that Cannot be Manipulated with the Fields of Force

(67) If the electrode matrix is sufficiently dense (with dimensions comparable to or smaller than the cells), so as to be able to perform selective lysis on cells even without having selected them beforehand, the method of the invention can still be completed, in particular if the cells to be preserved, presenting different characteristics from the non interesting cells, are sensitive to stimuli carried out at different frequencies of voltages applied to the electrodes.

(68) 5. Simplified Microfluidic Package

(69) It is not necessary to have a double microchamber, but a single compartment is sufficient, and the recovery need not be selective, so the contamination is not linked to the characteristic of the recovery flow.

(70) Any sensors integrated in the chip will be used to

(71) 1. determine the interesting particles.

(72) 2. Check the lysis of the undesired cells.

(73) Method of Ultra-Purification of Cells

(74) With enrichment techniques it is often easy to eliminate cells present in proportions greater than the interesting cells by several degree of magnitude (for example with centrifugations in gradients of density or enrichment with magnetic balls, etc.). However it is sometimes difficult to eliminate the few contaminating cells that remain (for example present in a proportion of 0.1-10%) to obtain a 100% pure sample. This is required for example if one wants to cultivate the interesting cells but these proliferate less rapidly than the non interesting ones, which, even if present in a low percentage, would then prevail downstream from the proliferation.

(75) As in the selection method described previously, the cells are introduced into the microchamber, the cells optionally line up in points of stable equilibrium near the electrodes (PEQ), and the contaminating cells are eliminated by lysating them with the electrodes, obviously after having identified them with suitable integrated or external sensors, or on the basis of intrinsic differences such as the frequency of the voltage applied to the electrodes which produces lysis.

(76) In this case too, the integrated sensors, if they exist, can optionally be used to

(77) 1. determine the interesting particles.

(78) 2. Check the lysis of the undesired cells.

(79) The 100% pure cells are then recovered, flushing out the sample.

(80) Based on this aspect of the invention, a method is therefore actuated for the ultra-purification of interesting particles from contaminating particles, both contained in a population of particles, characterised in that the isolation method described above is applied, where step b) is applied only to the contaminating particles.

(81) Method of Cell Analysis

(82) The study at biomolecular level of DNA and/or of proteins in single cells is increasingly interesting. According to an aspect of the present invention, a method is proposed for selecting and shifting selected cells possibly from a multiplicity of cells from a first multiplicity of points, and bringing them to a second multiplicity of points of analysis of micrometric dimensions, each point of analysis comprising at the most one single cell. The cell is lysated and its content is analysed on the chip, for example according to known techniques such as PCR and/or capillary electrophoresis on chip.

(83) Based on the invention, a method is therefore supplied for the analysis of particles, characterised in that it comprises the steps of:

(84) a) introducing said particles, suspended in a fluid, into a microchamber;

(85) b) shifting said particles, selectively, each into a predetermined point of analysis separate from said microchamber, but hydraulically connected to it;

(86) c) applying to said particles present in said predetermined points of analysis a method of selective lysis as described above;

(87) d) applying a defined analysis protocol on site to the respective debris of the lysis of said particles;

(88) where said defined analysis protocol is chosen from the group including: PCR, capillary electrophoresis on chip; combinations of the previous ones.

(89) Cell Analysis Apparatus

(90) To carry out the methods described, in particular the previous method of analysis, an apparatus is preferentially used as illustrated in the FIGS. 7, 8 and 9. The apparatus (FIG. 7) contains an array of electrodes as in the prior art, but it is characterised by a main microchamber (CHM) and by a multiplicity of secondary microchambers (CHJ). The main microchamber may be filled with a sample comprising at least one cell through the respective inlets (IM1) and outlets (OM1). Each secondary microchamber (CHJ) is of larger dimensions, preferably substantially comparable to those of a cell, as shown in FIG. 7. Preferably each secondary microchamber is connected to the main microchamber through a channel (LCHG) with a configuration (length and/or shape) sufficient to prevent (avoid or at least limit) the dispersion of the sample by diffusion and contamination towards other microchambers, in the time necessary for the analysis. According to a possible variation (FIG. 8), there is a multiplicity of secondary microchambers for lysis (CHLJ) connected to a channel for capillary electrophoresis on chip, for example with a cross junction (TJ). Alternatively a series of channels for capillary electrophoresis may be produced with a double T junction, according to the prior art. Optionally, at the end of the channel for capillary electrophoresis there is an integrated sensor (SENS_J), of an impedenziometric and/or optical type, able to produce an electropherogram based on the migration time of the compounds analysed from the junction (cross or double T) to the sensor itself. A further variation is illustrated in FIG. 9, where each microchamber of said multiplicity is connected to a capillary for electrophoresis (CAPJ) through a fluid outlet (OJ) of each secondary microchamber.