EP2429705B1 - Assembly formed by a filtration membrane and a support plate - Google Patents

Description

The present invention is in the field of microbiological testing equipment for liquid phase products.

Qualitative or even quantitative analysis of the presence of contaminants such as microorganisms is necessary to perform fluid sterility tests.

Thus, the detection and analysis of particles, living or not, contained in liquid or gaseous fluids, food, pharmaceutical, biological, cosmetic or hygiene products, as well as the monitoring of fermentation processes, comprises in general, a step of depositing the particles on a support and the optical analysis, for example by scanning, of the surface of this support.

The present applicant has developed a technique whereby the particles are retained on a filter membrane, after which it is brought into contact with a material capable of reacting with the contaminating particles to mark them, so that the labeling product reacts with the enzymatic activity of the contaminant to create a fluorescent signal.

It is then sufficient to carry out an analysis, in particular by laser excitation of the membrane to check if contaminants are present and in what number.

Such a technique has largely supplanted that of collecting the possible contaminants, transfer them to a Petri dish and wait for their development to carry out the appropriate tests.

The implementation of the aforementioned technique, developed by the present applicant, requires the transfer of the filtration membrane on a support plate which generally comprises a cellulose element or pad impregnated with a marking solution of viable microorganisms.

When placing this membrane on the support plate, there is the problem of the possible creation of an air bubble between the membrane and the cellulose pad, this air bubble forming a screen which opposes the correct and complete reaction between the labeling product and the microorganisms.

To solve this problem, users are invited to place the membrane on the support plate, not according to a single gesture generally directed perpendicular to the support plate, but in a two-phase gesture comprising first contacting the periphery of the membrane with the plate, then the application of the rest of the membrane against this plate. This "split" manipulation makes it possible to expel the air present between the membrane and its support.

In practice, many users use this methodology.

However, it requires that said operator does not forget to implement it. If he forgets, the test carried out can not be retained as valid, since the marking material will not have completely fulfilled its function.

The prior art can be illustrated by DE 10 339 083 , EP1 449 553 , US 4,783,321 , WO99 / 0065 and FR 2 801 660 , the features of the preamble of appended claim 1 being known from the latter document.

The present invention therefore aims to solve the difficulty detailed above by providing means for correctly positioning a membrane on its support plate, so as to prevent the creation of an air bubble between them.

Thus, a first object of the invention consists of a set of activation and / or microbiological contaminant disclosure consisting of a flat and rigid filtration membrane, and a generally flat plate, receiving and supporting this membrane, in particular for the purpose of activating and / or revealing immobilized contaminants thereon, this support plate comprising retaining and immobilizing means capable of cooperating with the periphery of the membrane.

According to the invention, said means comprise at least one non-deformable member which protrudes above the general plane of said plate, and which comprises at least one tab forming a stop, generally perpendicular to said plane, which is extended by a retaining appendage generally parallel to said plane, so that the engagement of said membrane with this member can be done only in a first movement of the membrane substantially parallel to the plane of the plate, followed by a second movement substantially perpendicular to said plane and that the plate ( 5) comprises, in its central part, a reservation (R) for receiving a material for marking or revealing said contaminants.

The presence of at least one non-deformable member constitutes an obstacle that opposes the direct engagement of the membrane on the plate in a directional movement generally perpendicular to the plane thereof.

Thanks to the characteristics of the invention, it is therefore possible to set up the membrane on the plate only according to the two aforementioned movements, so that the operator does not have to worry about or remember operations to to implement, since the objects he manipulates include means that will guide him in the implementation of his manipulations.

By the term "membrane" is meant both a self-supporting membrane, a flexible filtration structure attached to a rigid frame.

By the expression "first movement of the membrane substantially parallel to the plane of the plate", it is to be understood that, in carrying out this operation, the membrane occupies a position very close to the plate, parallel to it, or, at the very least, forming with it, an acute angle of not more than a few degrees (10 to 15 ° maximum).

• il comprend au moins un second organe formant organe de verrouillage, qui fait également saillie au dessus du plan général de ladite plaque, cet organe étant déformable élastiquement, de sorte que lors dudit second mouvement, il s'escamote puis reprend sa position initiale, verrouillant ainsi la membrane ;
• ledit organe non déformable est situé à l'opposé et en regard dudit second organe ;
• ladite membrane est pourvue d'un ergot apte à coopérer avec ledit organe non déformable ;
• ledit ergot a, vu de dessus, la forme générale d'un "T" ;
• ladite membrane est pourvue d'un ergot apte à coopérer avec ledit second organe ;
• ledit ergot a, vu de dessus, la forme générale d'une croix latine ou grecque ;
• ladite membrane s'inscrit dans un cercle, ledit ergot s'étendant radialement, à la périphérie de ce cercle ;
• ladite plaque comporte une région qui supporte ledit second organe et qui est séparée du reste de la plaque par une zone d'affaiblissement mécanique, de sorte que suite à un effort mécanique exercé sur cette région, on lui donne une orientation particulière par rapport au reste de la plaque, qui permet de libérer la membrane dudit second organe ;
• ladite région forme un appendice par rapport au reste de la plaque, ladite zone d'affaiblissement se situant à leur frontière.

According to other advantageous characteristics of this set:

• it comprises at least one second member forming a locking member, which also protrudes above the general plane of said plate, this member being elastically deformable, so that during said second movement, it retracts and then resumes its initial position, locking thus the membrane;
• said non-deformable member is located opposite and opposite said second member;
• said membrane is provided with a lug adapted to cooperate with said non-deformable member;
• said lug has, seen from above, the general shape of a "T";
• said membrane is provided with a lug adapted to cooperate with said second member;
• said pin has, seen from above, the general shape of a Latin or Greek cross;
• said membrane is in a circle, said lug extending radially at the periphery of this circle;
• said plate comprises a region which supports said second member and which is separated from the rest of the plate by a zone of mechanical weakening, so that following a mechanical force exerted on this region, it is given a particular orientation with respect to the rest the plate, which allows to release the membrane of said second member;
• said region forms an appendage with respect to the remainder of the plate, said weakening zone being at their boundary.

Other features and advantages of the present invention will appear on reading the detailed description which follows of a preferred embodiment.

• Les figures 1 et 2 sont des vues en perspective d'un réceptacle et d'une embase formant socle pour ce réceptacle, ces deux éléments étant constitutifs d'un dispositif de test ;
• La figure 3 est une vue en perspective du réceptacle qui apparaît sur les figures 1 et 2 ;
• La figure 4 est une vue de dessus d'une membrane constitutive de l'ensemble et du dispositif selon l'invention ;
• La figure 5 est une vue en perspective de l'embase apte à coopérer avec le réceptacle de la figure 3, cette embase étant ici pourvue d'une membrane et d'un capuchon de prélèvement de cette dernière ;
• La figure 6 est une vue de côté du capuchon apparaissant sur la figure 5 ;
• La figure 7 est une vue de dessus de la plaque du support constitutif de l'ensemble selon la présente invention ;
• La figure 8 est une vue en perspective de la plaque de la figure 7 ;
• La figure 9 est une vue en coupe selon le plan IX-IX de la figure 7 de la plaque de support, cette vue étant plus particulièrement destinée à expliquer la façon dont on met en place une membrane sur cette plaque ;
• La figure 10 est une vue de dessus analogue à la figure 7, sur laquelle la silhouette de la membrane a été repérée en traits interrompus.

This description will be made with reference to the appended drawings in which:

• The Figures 1 and 2 are perspective views of a receptacle and a socket base for this receptacle, these two elements constituting a test device;
• The figure 3 is a perspective view of the receptacle that appears on the Figures 1 and 2 ;
• The figure 4 is a top view of a membrane constituting the assembly and the device according to the invention;
• The figure 5 is a perspective view of the base adapted to cooperate with the receptacle of the figure 3 , this base being here provided with a membrane and a cap of the latter;
• The figure 6 is a side view of the hood appearing on the figure 5 ;
• The figure 7 is a top view of the support plate constituting the assembly according to the present invention;
• The figure 8 is a perspective view of the plate from the figure 7 ;
• The figure 9 is a sectional view along plane IX-IX of the figure 7 of the support plate, this view being more particularly intended to explain the manner in which a membrane is placed on this plate;
• The figure 10 is a top view similar to the figure 7 , on which the silhouette of the membrane was spotted in broken lines.

The receptacle 1 and the base 2 shown in FIGS. Figures 1 and 2 annexed are part of a microbiological test device.

The receptacle 1 is intended to receive the liquid product that is proposed to test. It has, as it were, a dual function of container and funnel.

It comprises a plastic bottle 10, closed by a removable cap 11, which is provided with openings for connection to a pump, for example.

This container is preferably transparent so that the operator can view the level of liquid that it contains.

Its lower part is referenced 12, and a part with the bottle, has the general shape of a cylindrical peripheral skirt.

As shown more particularly in figure 3 , this lower part is provided with two notches 120 arranged facing each other, whose function will be explained later.

It also has two openings 121 of square shape which are also facing.

Here again, the function of these openings will be explained later.

As this also shows figure 3 , the bottom of the container 10, which ensures its connection with the lower part 12, is open at its center to provide a circular passage 13 whose lower side is lined with a seal 130.

This receptacle 1 is intended to cooperate with a base 2 forming a base.

This base 2 has a generally cylindrical shape and its peripheral outer wall is, as shown in FIG. figure 5 , provided with two extra thicknesses 23 intended to cooperate with the complementary notches 120 of the lower part 12 of the receptacle 1.

This base also comprises two tabs 21, elastically deformable, each carrying a finger 210 intended to engage in the openings 121 of the lower part 12 of the receptacle. These legs 21 are integral with the base 2. They are directed parallel to its longitudinal axis and separated from the rest of the base.

Under these conditions, it is understood that the movement of engagement of the receptacle 1 on the base 2 is guided by the extra thicknesses 23 and the notches 120, while the locking of the receptacle on the base is done automatically, by ramp effect, via the elastically deformable tabs 21.

The separation of these two elements is done by pressing the tabs 21 so as to return slightly towards the center and thus clear the fingers 210.

Although this is not clearly visible in the figures, the base 2 comprises, parallel to and above a bottom wall 22 provided with a discharge orifice 23, a perforated surface formed of a network of grooves. concentric, which constitutes a filtration surface.

Such a structure advantageously replaces a sintered glass surface which previously required to be completed by the use of a cellulose filter support.

This filtration surface is intended to receive a rigid filtration membrane such as that represented in FIG. figure 4 .

This filtration membrane consists of a filtration structure 31 disposed on a rigid peripheral frame 30 of circular shape.

This frame 30 consists for example of a molded plastic material, while the structure 31 of the membrane is for example based on polyethylene terephthalate of a usual thickness of the order of 23 microns and variable porosity of 0.1 a few micrometers.

As shown in this figure, the membrane is provided with two diametrically opposed lugs.

They form an integral part of frame 30 and came from matter with him.

They extend in the same plane as the frame 30.

The lug 32 has the general shape of a "T" with a base 320 which extends in a radial direction, and a transverse bar 321 slightly curved, which extends perpendicularly to this base.

The second lug has the shape of a Latin or Greek cross, with a radial base 330, and a transverse branch 331.

The interest and function of these forms will be explained later.

This membrane is intended to be positioned on the filtration surface of the base 2 described above so that the structure 31 is superimposed on the aforementioned network of concentric grooves.

To do this and as shown in the figure 5 , the base 2 comprises a cutout 24 for the engagement of the lugs 32 and 33, respectively. This cut forms at the same time a means of immobilization and foolproofing.

When the test liquid has been filtered, the possible contaminants it contains are retained on the structure 31 of the membrane 3.

The test operation then consists of marking and / or revealing these contaminants so that they can be visualized or even counted.

To do this, it is necessary to take the membrane in place on the base 2 in a sterile manner. Indeed, in the opposite case, the manipulation of the membrane by the operator would bring other types of contaminants.

For this, use is made of a sampling cap 4 which appears to the figures 5 and 6 .

This cap essentially comprises a peripheral cylindrical skirt 4 whose outside diameter corresponds, with the clearance, to the outside diameter of the frame 30 of the membrane 3.

This peripheral skirt comprises two indentations 41 diametrically opposite one another, directed parallel to the generatrices of the constituent cylinder of the skirt.

Each indentation 41 has an enlarged lower portion 420 with convergent edges 420. In the state shown in FIG. figure 6 , the spacing between the edges 420 is smaller than the width of the bases 320 and 330 of the lugs 32 and 33 of the membrane.

The cap 4 is also provided with two diametrically opposed lugs 44 that protrude upwards above the skirt 40. They are angularly spaced notches 41 of 90 °.

Moreover, a gripping hand 43 extends perpendicularly to the ears 44.

This cap 4 is intended to engage on the membrane 3 when it is positioned on the base 2.

This movement is done from top to bottom according to the arrow f of the figure 6 while the indentations 42 are positioned vertically above the lugs 32 and 33 with respect to their bases 320 and 330.

By relying on these lugs, the convergent edges 420 deviate by elastic deformation and snap elastically on these lugs so as to join.

This movement of separation is symbolized by the arrows g of the figure 6 .

To carry out the reverse maneuver, that is to say to detach the membrane 3 from the cap 4, it suffices to exert pressure on the ears 44 in the direction of the arrow h, which separates the two opposite parts of the skirt 40 in the direction of the arrow j, and then releases the lugs of the membrane.

This "release" operation of the membrane is carried out so as to effect its transfer on a receiving and support plate which appears in particular to figures 7 and 8 . This plate is intended to allow the marking and / or the revelation of the contaminants carried by the membrane 3.

This support plate 5 full, that is to say not perforated, is a molded plastic plate, generally flat, median plane referenced P to the figure 9 .

This plate is provided with an appendix 53, which is in the plane P above and which is in one piece with the rest of the plate.

This appendix 53 comprises, in its zone of attachment to the remainder of the plate, a line of mechanical weakening 530, materialized by a groove whose function will be explained later.

The plate comprises on its upper surface, integrally molded, a central circular wall 50 whose diameter is equal to the inner diameter of the frame 30 of the membrane 3.

Inside the reservation R delimited by this wall, are arranged elongate shaped studs 500.

This reservation R is intended to accommodate a material such as a cellulose pad impregnated with a material capable of marking or revealing the contaminants carried by the membrane.

The plate 5 also comprises other walls 51, which are formed of sections, and which materialize the edge of the plate.

These walls are part of a circle whose diameter is slightly greater than the outer diameter of the membrane 3.

The plate 5 comprises means for retaining and immobilizing the membrane 3.

These means comprise a non-deformable member 6, which is positioned opposite and opposite the appendix 53.

This member 6 consists of a tab 60 forming a stop, which extends from the plate 5 vertically upwards, in a direction generally perpendicular to the plane P.

This tab extends, parallel to the plane P, by three horizontal appendages 61.

Moreover, the aforementioned appendix 53 comprises a second member 7 forming a locking member, which also projects above the general plane and the plate, this member 7 being elastically deformable.

As shown more particularly by Figures 8 and 9 this member 7 has the shape of a hook, with a foot 70 perpendicular to said plane P, and a locking pin 71, generally parallel to this plane P.

The installation of the membrane on the support is done as follows.

With the aid of the aforementioned cap 4, the lug 32 of the membrane 3 is positioned in a movement substantially parallel to the plane of the plate 5 and represented by the arrow k at the figure 9 .

In any case and in the absence of strictly parallel movement, the axis formed by the membrane 3 and the plane P is an acute angle α of a few degrees.

In doing so, the transverse bar 321 of the lug 32 is engaged inside the non-deformable member 6.

Then, by a movement symbolized by the arrow 1 and directed substantially perpendicularly to the plane P, then the rest of the membrane is engaged so that the second pin 32 elastically deforms the member 7 in the direction of the double arrow m, the finger 71 then coming to lock on the pin 33.

It is clear that due to the non-deformable nature of the member 6, any other method of engagement of the membrane on the plate is not possible, in particular in a movement perpendicular to the plate. The movement described above allows to expel the air and thus prevents the formation of a bubble between the membrane and the cellulose pad placed on the plate, which ensures the operator of a good marking or good revelation of the membrane by the material soaking the cellulose.

In any case, the operator does not have to ask the question of having done or not the right thing to do, since the means that equip the plate guide him and allow him to realize only the required gesture.

When the operation has been carried out, the membrane 3 occupies the position shown in dashed lines at the figure 10 .

Once this operation is performed, it is then sufficient to incubate the membrane 3 on its support plate 5 inside a chamber provided for this purpose, for a time and at a temperature specific to the protocol to be implemented.

To separate the membrane 3 from the plate 5, a force directed from the top to the bottom (according to the arrow q of the figure 9 ) on appendix 53. This causes it to break at the weakening zone 530, at least its tilting, in the direction of the arrow r, with respect to the plate 5.

Thanks to this movement, the lug 7 disengages from the membrane 3, so that it is possible to remove it.

Of course, if the membrane is to be the subject of other test operations, it will be removed with the cap 4 described above.

Claims (10)

1. Assembly for the activation and/or for the revelation of microbiological contaminants, consisting of a flat rigid filtration membrane (3), and a roughly flat plate (5), for receiving and supporting this membrane (3), in particular with a view to activating and/or revealing contaminants immobilised thereon, this support plate (5) comprising holding and immobilisation means able to cooperate with the periphery of the membrane (3), characterised by the fact that said means comprise at least one non-deformable member (6) that projects above the overall plane of said plate (P), and comprises at least one tab (60) forming a stop, roughly perpendicular to said plane (P), which is extended by a holding appendage roughly parallel to said plane, so that said membrane (3) can be engaged with this member (6) only in a first movement (k) of the membrane substantially parallel to the plane (P) of the plate, followed by a second movement (1) substantially perpendicular to said plane (P), and in that plate (5) comprises, in its central part, a recess (R) for receiving a material for marking or revealing said contaminants.
2. Assembly according to claim 1, characterised by the fact that it comprises at least one member (7) forming a locking member, which also projects above the overall plane (P) of said plate (5), this member (7) being elastically deformable, so that, at the time of said second movement (1), it retracts and then resumes its initial position, thus locking the membrane (3).
3. Assembly according to claim 2, characterised by the fact that said non-deformable member (6) is situated opposite and facing said second member (7).
4. Assembly according to one of the preceding claims, characterised by the fact that said membrane (3) is provided with a lug (32) able to cooperate with said non-deformable member (6).
5. Assembly according to claim 4, characterised by the fact that said lug (32) is, seen from above, in the general shape of a "T".
6. Assembly according one of claims 2 to 5, characterised by the fact that said membrane (3) is provided with a lug (33) able to engage with said second member (7).
7. Assembly according to claim 6, characterised by the fact that said lug (33) is, as seen from above, in the general shape of a Latin or Greek cross.
8. Assembly according to one of claims 4 to 7, characterised by the fact that said membrane (3) fits in a circle, said lug (32; 33) extending radially, at the periphery of this circle.
9. Assembly according to one of claims 2 to 8, characterised by the fact that said plate (5) comprises a region (53) that supports said second member (7) and is separated from the rest of the plate by a mechanical weakening zone (530), so that, following a mechanical force exerted on this region (53), it is given a particular orientation with respect to the rest of the plate (5), which makes it possible to release the membrane (5) from said second member (7).
10. Assembly according to the preceding claim, characterised by the fact that said region (53) forms an appendage with respect to the rest of the plate (5), said weakening zone (530) being situated at their boundary.

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