Hand-held microfluidic detection device that uses a parasitic light suppressing mechanism to reduce background noise

Abstract

The present invention relates to a hand-held microfluidic detection device, comprising: a microfluidic cell (M) having at least one chamber intended to at least contain a sample; a support (S) comprising a housing for the removable attachment thereto of the microfluidic cell (M); excitation light means arranged at least in part in the support (S) to side illuminate the at least one chamber of the microfluidic cell (M) to excite the sample contained therein; an optical detector (D) configured and arranged to detect light emitted from the sample when excited with said side illumination; and a casing (C) constituting an envelope into which at least the support (S) is housed and attached.

Claims

1. A hand-held microfluidic detection device, comprising: a microfluidic cell having at least one chamber intended to at least contain a sample; a support configured for the attachment thereto of said microfluidic cell; an excitation light arrangement arranged at least in part in said support to side illuminate said at least one chamber of said microfluidic cell to excite said sample contained therein; and an optical detector configured and arranged to detect light emitted from said sample when excited with said side illumination; wherein the device further comprises a casing constituting an envelope into which at least said support is housed and attached, and in that said support comprises a housing for removably attaching said microfluidic cell, wherein said microfluidic cell is a microfluidic flow cell where said at least one chamber is a channel for containing said sample flowing there within, wherein said support includes a fluidic manifold configured to fluidically communicate at least one manifold fluidic channel thereof with said at least one channel when the microfluidic flow cell is attached to the support, wherein said optical detector is configured and arranged to detect first light rays of said light emitted from said sample which depart from the sample according to one or more first emission directions going towards the optical detector, and wherein the device further comprises a parasitic light suppressing mechanism configured to avoid the impingement on the optical detector of second light rays of the light emitted from the sample or from another location of the microfluidic cell, which depart therefrom according to second emission directions opposed to sad first emission directions, or to at least attenuate the intensity of said second light rays before impinging on the optical detector, wherein the support comprises a plate with a through hole and a coupling arrangement to removably couple the microfluidic cell over said through hole, and wherein the optical detector is arranged below said through hole to receive and detect said first light rays emitted from the sample and passing through the trough hole, wherein said microfluidic cell is a microfluidic chip having a translucent plate with first and second opposite major surfaces sandwiching said at least one channel, wherein when the microfluidic chip is attached to the support said first major surface faces the optical detector, and wherein said parasitic light suppressing mechanism comprises at least a first deflection arrangement configured to deflect said second light rays once they have transmitted through said translucent plate through said second major face so that they either do not impinge on the optical detector or their intensity is attenuated before impinging on the optical detector, and wherein said first deflection arrangement comprises one or more first deflection walls arranged over said second major surface of the translucent plate of the microfluidic chip and extending perpendicularly or divergently with respect to said second major surface from first ends up to second ends.

2. The device according to claim 1, wherein said parasitic light suppressing mechanism further comprises a second deflection arrangement configured to deflect the second light rays once they have been deflected by said first deflection arrangement.

3. The device according to claim 2, wherein said second deflection arrangement comprises one or more second deflection walls extending convergently towards the second major surface of the translucent plate of the microfluidic chip from first ends, placed at a plane arranged over the second ends of the first deflection walls, up to second ends.

4. The device according to claim 3, wherein the one second deflection wall of the second deflection arrangement forms one of a cone and a convex curved cap.

5. The device according to claim 3, wherein the second deflection walls of the second deflection arrangement form a pyramid.

6. The device according to claim 3, wherein two second deflection walls of the second deflection arrangement converge, at their second ends, into a longitudinal edge.

7. The device according to claim 6, wherein a projection of said longitudinal edge on the second major surface of the translucent plate of the microfluidic chip follows a direction that is orthogonal or substantially orthogonal to a main illumination plane of said side illumination.

8. The device according to claim 7, wherein a longitudinal axis of said at least one channel of the microfluidic chip, when the microfluidic chip is attached to the support, occupies said main illumination plane.

9. The device according to claim 8, wherein the microfluidic chip comprises at least two of said at least one channel, one of them being configured and arranged so that a longitudinal axis thereof, when the microfluidic chip is attached to the support, occupies an illumination plane that is parallel to said main illumination plane and orthogonal or substantially orthogonal to said projection of said longitudinal edge.

10. The device according to claim 7, wherein said longitudinal edge belongs to a plane that is parallel or substantially parallel to the second major surface of the translucent plate of the microfluidic chip, when the microfluidic chip is attached to the support.

11. The device according to claim 3, wherein the casing comprises a top portion having a region which defines said plane at which the first ends of the one or more second deflection walls are placed.

12. The device according to claim 1, wherein the one first deflection wall of the first deflection arrangement forms a hollow truncated cone.

13. The device according to claim 1, wherein the one first deflection wall of the first deflection arrangement is one cylindrical wall that forms a hollow cylinder.

14. The device according to claim 1, wherein the first deflection walls of the first deflection arrangement form a hollow truncated pyramid.

15. The device according to claim 1, wherein the casing comprises a through opening defined at a wall thereof, wherein said through opening is configured and arranged to allow the introduction/extraction there through of the microfluidic cell with respect to the casing and the coupling/uncoupling thereof by said coupling arrangement.

16. The device according to claim 1, wherein said optical detector is also housed into said casing.

17. The device according to claim 1, further comprising an electric and electronic system operatively connected to said optical detector, to power and control the operation thereof and also to receive and process detection signals generated thereby to perform optical measurements, and connected to said excitation light arrangement, to power and control the operation thereof, and to a user interface included in the device which includes at least a user input mechanism and a display to control the operation of the device by a user and display at least graphical information related to said optical measurements.

18. The device according to claim 1, wherein the support further comprises liquid and pneumatic connectors for liquid delivery and collection to/from the at least one manifold fluidic channel, wherein said connectors are accessible from outside the casing to removably couple thereto at least one of the following components: liquid and/or gas reservoirs, external pumps, valves and actuators.

19. The device according to claim 1, wherein said excitation light arrangement comprises at least one light generating unit, wherein said light generating unit and/or an optical element directing light generated thereby is/are attached to the support such that a light beam generated by the light generating unit goes towards a respective side edge of the translucent plate of the microfluidic chip, either with an optical axis which is orthogonal to said side edge or with an optical axis which is transversal but not orthogonal to said side edge and has an emission direction away from the optical detector.

20. The device according to claim 1, further comprising a deformable sealing gasket configured and arranged to be placed, when the microfluidic chip is attached to the support, between the microfluidic chip and the support to ensure a gas-tight seal between the two.

21. The device according to claim 20, wherein said deformable sealing gasket comprises two or more O-rings interconnected through a film frame, thinner than the two or more O-rings, so that each of the two or more O-rings is configured and arranged to be positioned, when the microfluidic chip is attached to the support, in correspondence with a respective opening of the at least one channel of the microfluidic chip and a respective opening of the at least one manifold fluidic channel, wherein said film frame defines a central through-opening configured and arranged to be in correspondence with said through hole of the plate of the support.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) In the following some preferred embodiments of the invention will be described with reference to the enclosed figures. They are provided only for illustration purposes without however limiting the scope of the invention.

(2) FIG. 1 is an exploded and schematic perspective view of the device of the present invention, for an embodiment.

(3) FIG. 2 is a cross-section view which schematically shows the device of the present invention, for another embodiment, including the casing and some of the elements placed within the casing.

(4) FIG. 3 is a further cross-section view which schematically shows part of the device of the present invention, for another embodiment, illustrating particularly the microfluidic chip, the support including the manifold, two LEDs, a light blocking element, and some of the light suppressing arrangements.

(5) FIG. 4 is a top view of the support/manifold of the device of the present invention with a microfluidic chip coupled to the housing included therein, for an embodiment.

(6) FIG. 5 is a top view which shows the microfluidic chip of the device of the present invention, for an embodiment.

(7) FIG. 6 is a perspective view which shows part of the elements of the device of the present invention, for an embodiment, including the support/manifold, housing and coupling arrangement, microfluidic chip, first deflection walls, LEDs, connectors, and liquid and liquid/gas reservoirs connected to some of the connectors.

(8) FIG. 7 is a cross-section view of part of the elements depicted in FIG. 6, showing the interior of liquid and liquid/gas reservoirs.

(9) FIGS. 8 and 9 are perspective views similar to that of FIG. 6 (without the reservoirs), and including a spring mechanically linking the support and one of the first deflection walls which form part of a kind of cup which constitutes the housing and coupling arrangement for the introduction/extraction and coupling/uncoupling of the microfluidic chip thereto, FIG. 8 showing a situation where the microfluidic chip is introduced in the housing and coupled to the support, and FIG. 9 an intermediate situation representing the introduction or extraction of the microfluidic chip.

(10) FIG. 10 schematically shows an embodiment of the first and second deflection walls of the device of the present invention, including a cover element which comprises the second deflection walls; (a) shows a situation at which the cover element is distanced form the first deflection walls, which extend divergently upwards; and (b) shows a situation at which the cover element lays on the first deflection walls and covers the volume enclosed thereby.

(11) FIG. 11 is a view similar to that of FIG. 10(b), but differing therefrom in that the first deflection walls extend vertically upwards.

(12) FIGS. 12a to 12f schematically show part of the device of the present invention, for alternative embodiments differing from one another in that they include different arrangements of excitation light means.

(13) FIG. 13 shows an embodiment of a deformable sealing gasket to be placed between the microfluidic chip and the support of the device of the present invention.

(14) FIG. 14 is a cross-section of a perspective view of part of the device of the present invention, for an embodiment, obtained along a cutting plane that coincides with a main illumination plane that passes through the centre axes of the light sources, and where two second deflection walls correspond to two sides of a triangular prism and converge into a longitudinal edge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(15) As shown in FIGS. 1 and 2, the hand-held microfluidic detection device of the present invention comprises a casing C constituting an envelope and the following components housed within the casing C:

(16) a microfluidic cell M, which for the illustrated embodiments is a microfluidic chip M comprising inner channels Mc (see FIG. 5) for the containing and flow of a sample;

(17) a support S comprising a housing for removably attaching thereto the microfluidic chip M;

(18) excitation light means comprising LEDs G arranged in the support S tilted upwardly to side illuminate the inner channels Mc of the microfluidic chip M to excite the sample contained therein;

(19) an optical detector D (schematically shown in FIG. 2) configured and arranged to detect light emitted from said sample(s) when excited with the side illumination; and

(20) an electric and electronic system ES (schematically shown in FIG. 1) operatively connected to the optical detector D (through a flat cable, for the illustrated embodiment), to power the same and control the operation thereof and also to receive and process detection signals generated thereby to perform optical measurements, to the excitation light means, to power the same and control the operation thereof, and to a user interface included in the device which includes a touch screen T to control the operation of the device by a user and display graphical information related to the optical measurements.

(21) For the embodiment shown in FIG. 1, the casing C is formed by two casing halves Ca, Cb, attachable to each other to form the above mentioned enclosure.

(22) The support S is housed within the casing C and also attached to a structural inner element thereof, such as pillars K, for the illustrated embodiments, and, as shown in FIG. 4, includes a fluidic manifold configured to fluidically communicate manifold fluidic channels Sc thereof with the inner channels Mc when the microfluidic chip M is attached to the support S.

(23) As shown, among other, in FIGS. 2 and 4, the support S comprises a plate with a through hole H and a coupling arrangement to removable couple the microfluidic chip M over the through hole H.

(24) The microfluidic chip M is depicted in detail in FIG. 5, and has a translucent plate with first Ma and second Mb opposite major surfaces (see FIG. 2) sandwiching the inner channels Mc which are communicated with the exterior thereof through respective end openings Mco, all of them simultaneously coincide with respective manifold channels openings Sco (i.e. spatially aligned) when the microfluidic chip M is attached to the support S, as shown in FIG. 4 (where due to the translucency of chip M, the elements placed below can be seen), so that the inner channels Mc are communicated with the manifold channels Sc.

(25) With reference to FIG. 2, different light rays are depicted, one of them are first light rays 1, which are of interest for the detection, and are emitted from the sample (whether scattered, refracted, reflected, generated, or diffracted thereby) which depart from the sample according to one or more first emission directions going towards the optical detector D and pass through the trough hole H.

(26) As shown in FIG. 2, when the microfluidic chip M is attached to the support S the first major surface Ma faces the optical detector D, and the optical detector D is arranged below through hole H to receive and detect said first light rays 1.

(27) The rest of the above mentioned light rays depicted on FIG. 2, are second 2, third 3, and four 4 parasitic light rays.

(28) As already disclosed in a previous section, the device of the present invention comprises light suppressing means for avoiding the impinging of said parasitic light rays 2, 3, 4 on the optical detector D, or at least attenuating them before impinging on the optical detector D until a degree at which their negative effects become negligible.

(29) For the illustrated embodiments (see FIGS. 2, 3, 6, 8, 9, 10, and 11), the device comprises parasitic light suppressing means configured to avoid the impingement on the optical detector D of the second light rays 2 of the light emitted from the sample or from another location of the microfluidic cell, which depart therefrom according to second emission directions opposed to sad first emission directions, or to at least attenuate the intensity of said second light rays 2 before impinging on the optical detector D.

(30) Said parasitic light suppressing means comprises a first deflection arrangement configured to deflect the second light rays 2 once they have output said translucent plate through the second major face Mb so that they either not impinge on the optical detector D or their intensity is attenuated before impinging on the optical detector D.

(31) The first deflection arrangement comprises, for the illustrated embodiments, several first deflection walls W1 (particularly four) arranged over the second major surface Mb of the translucent plate of the microfluidic chip M and extending orthogonally with respect to the second major surface Mb of the translucent from first ends W1a up to second ends W1b (see especially FIGS. 2 and 10).

(32) For most of the depicted embodiments, the first deflection walls W1 extend divergently with respect to the second major surface Mb to form a hollow truncated pyramid which encloses a volume over a portion of the second major surface Mb, the second light rays 2 departing from said portion of the second major face Mb being deflected upwards by the inner surfaces of the first deflection walls W1, as represented by the light rays 2 in FIG. 2.

(33) Alternatively, for the embodiment illustrated in FIG. 11, the first deflection walls W1 extend perpendicularly with respect to the second major surface Mb, forming a hollow rectangular prism (such as a cuboid) or a hollow cylinder, which also encloses a volume over a portion of the second major surface Mb, and which inner surfaces also deflect light rays 2, but with an angle different the one shown in FIG. 2.

(34) For the illustrated embodiments, the parasitic light suppressing means further comprises a second deflection arrangement configured to deflect the second light rays 2 once they have been deflected by the first deflection arrangement.

(35) As shown in FIGS. 2, 10, and 11, the second deflection arrangement comprises one or more second deflection walls W2 extending convergently towards the second major surface Mb of the translucent plate of the microfluidic chip M from first ends W2a, placed at a plane P arranged over the second ends W1b of the first deflection walls W1, up to second ends W2b. As shown in FIG. 2, the light rays deflected by the inner surface of first deflection walls W1 are further deflected by the second deflection wall(s) W2.

(36) The wall or walls W2 (a cross-section of which is shown in FIGS. 2, 10 and 11) of the second deflection arrangement form one of a cone, a pyramid, and a convex curved cap, for some embodiments.

(37) For other embodiments, the wall or walls W2 converge, at their second ends W2b, into a longitudinal edge LE, as shown in FIG. 14, where two second deflection walls W2 correspond to two sides of a triangular prism and converge into a longitudinal edge LE.

(38) As shown in FIG. 14, the main illumination plane (that coincides with the cutting plane used to obtain the illustrated cross-section view) is orthogonal (or substantially orthogonal) to a projection of the longitudinal edge LE on the second major surface Mb of the translucent plate of the microfluidic chip M, and specifically, for the illustrated embodiment, orthogonal to the longitudinal edge LE, as the latter belongs to a plane that is parallel or substantially parallel to the second major surface Mb of the translucent plate.

(39) FIG. 14 also shows how one of the microfluidic channels Mc has a longitudinal axis, or flow path, that occupies the main illumination plane, and thus is also orthogonal at least to the projection of the longitudinal edge LE, and preferably to the longitudinal edge LE itself.

(40) The rest of microfluidic channels Mc are arranged so that their respective longitudinal axes, or flow paths, occupy respective illumination planes that are parallel to the main illumination plane.

(41) For the embodiment of FIG. 14, the first W1 and second W2 deflection walls have been illustrated forming an integral single piece. However, a slight variation of the illustrated embodiment, includes the first W1 and second W2 deflection walls into two separate pieces that are coupled to each other, similarly to what is shown in FIGS. 10 and 11, i.e. by means of a cover element having the second deflection walls W2 and arranged over the first deflection walls W1.

(42) For the embodiment shown in FIG. 2, the casing C comprises a top portion Ct having a region which defines plane P at which the first ends W2a of the one or more second deflection walls W2 are placed, and the light rays deflected by the inner surface of first deflection walls W1 are further deflected by the second deflection wall(s) W2 away from the microfluidic chip M.

(43) For some embodiments, the orthogonal distance between said region of the top portion Ct defining said plane P and the major surface Mb of the translucent plate of the microfluidic chip M goes from 2 cm up to 8 cm, preferably up to 5 cm.

(44) Alternatively, for the embodiments shown in FIGS. 10 and 11, the device of the present invention further comprises a cover element CE arranged over the first deflection walls W1 to cover the volume enclosed thereby, and said cover element CE comprises the one or more second deflection walls W2 and a top portion having a lower surface defining said plane P, wherein, in use (see FIGS. 10(b) and 11), some regions of said top portion lower surface lay on the second ends W1b of the first deflection walls W1, said regions surrounding the second deflection wall(s) W2, and the second deflection wall(s) W2 occupying part of the volume enclosed by the first deflection walls W1.

(45) By comparing FIGS. 10(b) and 11, one can see that for the illustrated cross-sections the angle between the components of each pair of opposite first W1 and second W2 deflection walls is substantially the same for both embodiments, and calculated so that light rays 2 deflected by the inner surface of first deflection walls W1 are further deflected by the second deflection wall(s) W2, and in this case (in contrast to the embodiment of FIG. 2) go back to the first deflection walls W1 and come back therefrom a number of times, so that the light intensity thereof is highly attenuated.

(46) Preferably, the deflection surfaces of both the first W1 and the second W2 deflection walls are dark in order to absorb light.

(47) As shown in FIG. 2, third parasitic light rays 3 depart from LEDs G. In order to suppress, or at least attenuate said third parasitic light rays 3, light deflection elements are arranged to deflect said rays 3 to avoid the impingement thereof on the optical detector D. For the illustrated embodiment, said light deflection elements are implemented by the external surface(s) of some of the first deflection walls W1, which can be parallel to the inner surfaces thereof (as illustrated) or not. For a non-illustrated embodiment, the light deflection elements are implemented by walls which are not the first deflection walls W1. FIG. 2 also shows how four parasitic light rays 4 could have entered into the casing C from the exterior thereof, and that in order to suppress, or at least attenuate said four parasitic light rays 4, light deflection elements are arranged to deflect said rays 4 to avoid the impingement thereof on the optical detector D. For the illustrated embodiment, said light deflection elements are implemented also by the external surface(s) of some others of the first deflection walls W1.

(48) For another embodiment, shown in FIG. 3, the device of the present invention further comprises a tubular light blocking element W3 extending from a lower surface of the support's plate surrounding its through hole H, and having a lower open end W3o into which the optical detector D (not shown in FIG. 3) is to be arranged such that it receives the first light rays 1 going through the interior of the tubular light blocking element.

(49) Said tubular light blocking element W3 is configured to block the impingement on the optical detector D of any possible parasitic light ray which has not been suppressed by the above mentioned parasitic light suppressing means and further parasitic light suppressing means, or that could have entered into the dark compartment enclosed by the casing C.

(50) With reference now to FIGS. 8 and 9, they show how the first deflection walls W1 are integrated into a cup element Q which also includes front retaining fingers F (implementing the above mentioned coupling arrangement to removable couple the microfluidic chip M over the through hole H) and two pins n1 (only one of them can be seen in the figures, because the other is hidden by the cup element Q) extending from opposite first deflection walls W1. Said pins n1 are linked to respective pins n2 of the support S by respective springs Z. A back portion of the cup element is articulated to the support S, at articulation A, so that the cup element Q rotates there about.

(51) By releasing the retaining fingers F from a position at which they are coupled to the support S, the cup element Q pivots about articulation A up to an angular end position at which the springs Z are fully extended, as shown in FIG. 9, so that the above mentioned housing is defined between the cup element Q and the region of the plate of the support S surrounding the through hole H. Said region is side demarcated by guide frame elements Sg (from which the above mentioned pins n2 extend) which allow a guided introduction/extraction of the microfluidic chip M into said housing, as shown in FIG. 9.

(52) By pushing the microfluidic chip M further into the housing than the situation shown in FIG. 9, the chip M is properly placed at the right place (at which channels opening Mco are place just above channels openings Sco, so that channels Sc and channels Mc are communicated with each other), after having pushed upwards the back portion of the cup element Q, during the introduction displacement, such that the front portion thereof descends up to a position at which fingers F retain the microfluidic chip M in the support's housing, by the front end of the translucent plate thereof, as illustrated in FIG. 8.

(53) As shown in FIG. 8, a deformable sealing gasket J is placed between the microfluidic chip M and the support S to ensure a gas-tight seal between the two. In this embodiment, the cup element Q exerts pressure onto the removable microfluidic chip M in order to deform the gasket J and generate a pneumatic seal.

(54) An alternative embodiment for said deformable sealing gasket J is shown in FIG. 13, where the seal J comprises several O-rings Jr interconnected through a thin film frame Jf, thinner than the O-rings Jr, so that each of O-rings Jr is configured and arranged to be positioned, when the microfluidic chip M is attached to the support S, in correspondence with a respective opening Mco of the channels Mc of the microfluidic chip M and a respective opening Sco of the manifold fluidic channels Sc. As shown in the figure, the film frame Jf defines a central through-opening Ja configured and arranged to be in correspondence with the through hole H of the plate of the support S.

(55) The deformable sealing gasket J of FIG. 13 ensures that all the O-rings Jr are positioned in one step in a correct and precise positioning, including the benefits of the use of individual O-rings to avoid leaks, that provide a small contact surface as to allow a good sealing without having to apply important mechanical pressure on it (compared to a flat gasket of the same dimension than the chip for example), while doing without with the drawbacks that the use of individual O-rings has when the microfluidic chip has an important number of ports (i.e. of openings Mco) that are of very small dimensions, so are the dimensions of the O-rings, and when the O-rings positions may not be conserved correctly when removing the chip after use, reasons that make ensuring the sealing a complex task. Those drawbacks are solved by the inclusion of the above mentioned film frame Jf interconnecting the O-rings Jr.

(56) Both the support's housing and the coupling arrangement can be different to the ones illustrated for non-illustrated embodiments.

(57) Going back to FIG. 1, there is shown a through opening Ch defined at a wall of the casing C, particularly of casing half Ca, wherein said through opening Ch is configured and arranged to allow the introduction/extraction there through of the microfluidic chip M with respect to the casing C and the coupling/uncoupling thereof by the coupling arrangement, as described above.

(58) FIG. 1 also shows how the device of the present invention also comprises a lid L for closing casing's through opening Ch once the microfluidic chip M is introduced there through and coupled to the support S by the coupling arrangement, in order to block ambient light and other external agents from entering into the dark compartment enclosed by the casing C.

(59) FIGS. 2, 4, and 6, show how the support S of the device of the present invention further comprises, for the illustrated embodiments, liquid and pneumatic connectors/ports Cn1, Cn2, Cn3 for liquid delivery and collection to/from the at least one manifold fluidic channel, wherein said connectors Cn1, Cn2, Cn3 are accessible from outside the casing C through respective through openings Cao (see FIG. 1), to removable couple thereto at least one of the following components: liquid and/or gas reservoirs R.sub.GL, R.sub.L, external pumps and actuators.

(60) FIGS. 6 and 7 show one of said liquid reservoirs R.sub.L1 and one of said liquid/gas reservoirs R.sub.GL respectively coupled to connectors Cn2 and Cn1. Each of said liquid reservoir R.sub.L1 and liquid/gas reservoir R.sub.GL constitute a further independent aspect which could form another invention.

(61) Particularly, connector Cn1 comprises a liquid and a gas port enabling the pneumatic control of liquid transfer from the manifold to the removable microfluidic chip M and the collection of liquid therefrom in a closed and gastight container R.sub.GL when attached thereto through intermediate connector combined liquid-gas connector CR.sub.GL. The gastight container R.sub.GL comprises liquid reservoir R.sub.L and gas conduct R.sub.G (for the pneumatic control of the liquid transfer), having corresponding lower output channels R.sub.Lp, R.sub.GLp through which they are communicated with the manifold channels Sc. This feature of this connector Cn1 container R.sub.GL assembly is very important in many tests to safely dispose of biological samples and reagents after use.

(62) Regarding said liquid reservoirs R.sub.L1, for example for containing reagents, they can be connected to liquid ports Cn2, Cn3, for delivery to the manifold channels Sc and finally to the microfluidic chip channels Mc.

(63) For the embodiment shown in FIG. 7, the liquid reservoir R.sub.L1 has a connection head that fits into liquid port Cn2 and a vent hole R.sub.L1p on their opposite side. This vent hole R.sub.L1p allows for gas flow into the reservoir R.sub.L1 if the liquid is aspirated through the application of a negative pressure. It also allows the application of a positive gas pressure that can force liquid flow into the manifold channels Sc.

(64) For a non-illustrated embodiment, an external liquid valve is attached to the manifold in order to select which liquid to flow into the channels Mc of the removable microfluidic chip M from a selection of several reservoirs or input channels. In another non-illustrated embodiment, a liquid valve is embedded in the manifold. In another non-illustrated embodiment, a liquid pumping element is directly attached to or built into the manifold.

(65) In another non-illustrated embodiment, an external pneumatic valve is attached to the manifold in order to connect a gas channel Sc to a variety of other gas channels Sc that may be pressurized at different positive or negative pressures. In another non-illustrated embodiment, a pneumatic valve is embedded in the manifold. In another non-illustrated embodiment, a gas-pumping element is directly attached to or built into the manifold.

(66) In one embodiment, the light source is one light-emitting diode (LED). In another embodiment, the light sources are two LEDs placed on either side of the removable microfluidic component. In another embodiment, the light source is at least one laser. In another embodiment, the light source is at least one optical fibre. In another embodiment, the light source is a reflective coating applied to or fabricated on the surface of the fluid distribution device upon which light is projected or reflected.

(67) FIGS. 12a-12f schematically show (the support S has just been schematically represented by a rectangle) alternative embodiments of the device of the present invention, differing from one another in that they include different arrangements of excitation light means.

(68) Specifically, for the embodiment shown in FIGS. 12a and 12b, the excitation light means comprises two LEDs G, arranged on two respective side edges of the translucent plate of the microfluidic chip M, tilted upwards at FIG. 12a and orthogonally to said side edges at FIG. 12b.

(69) The embodiments shown in FIGS. 12c and 12d differ from those of FIGS. 12a and 12b in that the excitation light means comprises one laser source G arranged on one side edge of the translucent plate of the microfluidic chip M, tilted upwards at FIG. 12c and orthogonally to the side edge at FIG. 12d.

(70) For the embodiment shown in FIG. 12e, the excitation light means comprises a light source G and an optical fibre optically coupled thereto to direct light emitted thereby to one of the side edges of the translucent plate of the microfluidic chip M.

(71) For the embodiment of FIG. 12f light emitted by light source G is directed and lensed by tilted a tilted lens towards one of the side edges of the translucent plate of the microfluidic chip M.

(72) For anon-illustrated embodiment, instead or complementarily to the above mentioned lens, another optical element is placed between the light source G and the side edge of the microfluidic chip M, such as a reflective coating arranged on a specific region of the support S.

(73) Experimental Validation:

(74) The sample contained in the microfluidic channels Mc of the microfluidic chip M may consist of one or more areas of interest. In one implementation, the sample is distributed along a two-dimensional array, with the rows being defined by the channels Mc and the columns being arbitrary determined by the deposition of reagents to limited areas. Such a sample array simplifies test multiplexing and enables high-throughput screening in a reduced area and with a reduced consumption of reagents. Imaging such an array using conventional microscopy techniques may be laborious or result in images of low quality.

(75) In the device of the present invention, a fast, compact and cost effective method has been devised to image the above mentioned array with high sensitivity thanks to the reduction in background noise provided by the light suppressing and light blocking elements integrated in the support S. Thanks to this integration, the device is capable of imaging simultaneously the entire sample area of the microfluidic consumable (2020 mm) with better signal to noise ratio than a commercial microscopy system and in a fraction of the time (approximately 0.01 vs 10 minutes). Alternative array scanning systems have been previously described, but generally they are large and expensive laboratory instruments that cannot be easily transported and used at the point of care. The developments associated to the device of the present invention have enabled to deliver a measurement system of such capability at reduced cost, weight and dimensions.

(76) The present inventors have built a prototype of the device of the present invention, and performed detection measurements on a sample, and have also performed measurements on the same sample with a laboratory microscope, in order to perform a signal-to-noise values comparison.

(77) The table below shows the results obtained, in the form of signal over noise values for signals of varying intensities. The prototype of the present invention is called therein hand-held prototype (built according to FIGS. 1 to 9) and the laboratory microscope is a NIKON microscope, particularly model Nikon Eclipse Ti, with illumination by means of an halogen lamp associated to an Olympus U-DCD condenser, and with an objective Nikon S FLuor; 10/0.50.

(78) TABLE-US-00001 Signal-to-noise Signal Handheld Intensity prototype NIKON 100 5.56 2.08 80 3.88 1.93 75 3.52 1.89 65 3.03 1.65 50 2.46 1.48 30 1.55 1.23

(79) The results included in the above table prove that the device of the present invention provides such good detection results that improve not only those provided by hand-held devices but also those achieved by some commercial laboratory microscopes.

(80) A person skilled in the art could introduce changes and modifications in the embodiments described without departing from the scope of the invention as it is defined in the attached claims.