WO2013021274A1

WO2013021274A1 - Device for taking, preparing and transferring fecal samples, and corresponding method

Info

Publication number: WO2013021274A1
Application number: PCT/IB2012/001544
Authority: WO
Inventors: Paolo Galiano
Original assignee: Alifax Holding Spa
Priority date: 2011-08-10
Filing date: 2012-08-10
Publication date: 2013-02-14
Also published as: ITUD20110130A1

Abstract

Device for taking, preparing and transferring fecal samples comprising at least a test tube (13) able to contain a diluting solution and the fecal sample taken so as to obtain a diluted solution (37) of the fecal sample, and a collection and transfer unit (12) for the fecal sample able to be inserted inside the test tube (13), in which the collection and transfer unit (12) comprises a first stopper (14) to close the test tube (13), a tubular transfer member (18) associated externally with the first stopper (14) through which the diluted solution (37) is picked up or transferred toward the outside, a hollow rod (15, 1 15) associated internally with the first stopper (14) and able to be inserted into the test tube (13), on one side fluidically connected to the tubular member (18) and on the other side having at least a collection terminal (17, 117) for the fecal sample, passage ways being provided to put the inside of the test tube (13) in communication with the inside of the hollow rod (15), so as to allow the diluted solution (37) to flow from the test tube (13) toward the tubular member (18), through the hollow rod (15).

Description

"DEVICE FOR TAKING, PREPARING AND TRANSFERRING FECAL SAMPLES, AND CORRESPONDING METHOD"

FIELD OF THE INVENTION

The present invention concerns a pre-analytic medical device which is able to both take and contain fecal samples taken and to be analyzed, and to prepare the samples for subsequent analyses.

BACKGROUND OF THE INVENTION

In the medical field the need to take biological samples of a patient's feces is known, to subject them to one or more medical analyses. Usually, the sample is taken from the patient, either in a domestic setting or in a clinic, in the most varied ways, depending on the type of sample, and inserted in a collection test tube. The test tube is closed with a stopper, by the patient or by the health worker responsible, and delivered to the analysis laboratory. It is also known that, among the analyses which can generally be carried out, there is the test to verify the presence of occult blood in the feces. This test is recommended and is considerably increasing in the search for rectal colon cancer and indeed in Italy it is possible to carry out this test even at the chemist's.

Normally, the sample taken is inserted in a collection tube in which a measuring collimator is present, which standardizes the amount of feces collected. At the end of this operation, the feces are normally diluted in a solution which helps to detect hemoglobin inside the collection tube. Afterward, the diluted feces are made to pass through a filter to eliminate the corpuscular part of the feces, in order to make an extract of the feces react with suitable antiserums.

Different types of instruments are used to carry out this test: indeed there are dedicated automatic instruments which require the use of their own test tubes, or instruments of the clinical chemical type are used and, last but not least, also instruments which allow the application of manual methods, such as lateral flow tests. One disadvantage is that the test tubes used by the different instruments are not always interchangeable and this represents a complication and an obstacle which can slow down the execution and more widespread use of this clinical test.

In different analysis laboratories they prefer to use automatic dedicated instruments because, for example, instruments of the clinical chemical type lead to perplexity regarding sterility and sanitization because the fecal sample, even filtered, is not without bacteria which could colonize inside the instrument, thus invalidating other types of clinical or biological tests.

Document EP- A- 1.346.692 describes a collection device for the inspection of the sanitary conditions of the apparatuses, materials, machines, crockery and other objects used in the food industry, and also restaurant kitchens. This device includes a test tube, a stopper coupled to a hollow rod which has a swab at one end formed by a cotton wad or similar material able to be saturated and which, once impregnated with a diluent, is swiped on the object to be analyzed in order to collect the sample. Consequently, this device is in no way suitable to collect a fecal sample as discussed above, because cotton or equivalent material is a material which absorbs liquid and cannot therefore be used to collect a fecal sample for occult blood tests since it does not allow to compare the amount of fecal sample collected with the volume of diluting liquid necessary for the analysis.

Document EP-A-0.638.803 describes a device for the collection of a fecal sample which includes a container in which the fecal sample is disposed and which contains a diluting liquid, a stopper having a solid bar provided with a collection end which has recesses to house a quantity of fecal sample, a separating wall to remove the excess fecal sample, a filter disposed at the opposite end of the container with respect to the stopper, in order to filter the feces in suspension, and a portion downstream of the filter to deliver drops of filtered liquid. This known device, however, is complex, since it provides different components to collect the fecal sample, to filter the feces in suspension and to distribute drops of filtered liquid.

Document US-A-2004/0057876 describes a device to collect a sample of saliva, therefore it does not supply any teaching regarding the collection of a fecal sample for occult blood tests.

Document EP-A-0.354.704 describes a medical device for the collection of a sample for purposes of analysis which includes a collection swab made of cotton or equivalent material.

Also document US-A-201 1/004122 describes a device for the collection of a sample provided with a collection terminal formed by swab made of cotton or equivalent material.

Consequently, these known devices too, because of the configuration of the collection swab made of cotton or equivalent material, are unsuitable for the collection of a fecal swab for occult blood tests, as discussed above.

One purpose of the present invention is to offer, for the type of test in question, a simplification for the collection of the fecal sample inside a single test tube which is adaptable, according to requirements, both to dedicated automatic instruments and to chemical clinical instruments, and also to a manual method using rapid lateral flow tests.

Another purpose of the present invention is to render the use of the test tube with the fecal sample collected as sterile as possible, preventing the possible spreading of bacteria contained therein.

A further purpose is to perfect a method which allows to carry out the taking and preparation of the fecal sample first, and the corresponding analyses after, both simply and safely, irrespective of the type of instrumentation used.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a device for taking, preparing and transferring a fecal sample for occult blood tests according to the present invention comprises at least a test tube to contain a diluting solution and a unit to collect and transfer the fecal sample to be inserted inside the test tube in order to obtain, from the suspension of the fecal sample collected in the diluting solution, a diluted solution of the fecal sample contained in the test tube.

According to the present invention the collection and transfer unit comprises a first stopper to close the test tube, a tubular transfer member which protrudes externally from the first stopper and which has a longitudinal cavity through which the diluted solution is transferred from inside the test tube toward the outside, and a hollow rod which protrudes from the first stopper from the opposite side with respect to the tubular member and able to be inserted inside the test tube.

The hollow rod is axially aligned to the tubular member and has a first upper end coupled directly inside the longitudinal cavity of the tubular member, and is thus coupled inside the first stopper and fluidically connected to the tubular member.

In this way a direct axial passage way is defined of the diluted solution from the hollow rod through the tubular member arid toward the outside.

The hollow rod also has a second lower end to be positioned inside the test tube and bearing at least a collection terminal for the fecal sample, comprising a collection body which axially has a plurality of calibrated loop housings to collect the fecal sample.

Passage ways are provided to put the inside of the test tube in communication with the inside of the hollow rod, so as to allow the diluted solution to flow from inside the test tube toward the tubular member, through the hollow rod.

The proposed solution simplifies both the collection of the fecal sample inside the test tube, as well as the transfer of the diluted solution of fecal sample toward the outside, so that it is adaptable, according to requirements, both to dedicated automatic instruments and also to clinical chemical instruments, and for manual methods too. In particular, the device of the present invention can be used on each occasion both with dedicated analytical instruments, for analyses on slides and also for non dedicated open instruments.

Moreover, using the same hollow rod which has the collection terminal also to transfer the solution of diluted sample to the outside renders the device simpler and more economical.

The test tube used is also simple to construct and, in particular, does not require that the lower end of the test tube, opposite the one where the hollow rod is introduced, is dedicated and configured in a complex way to deliver the solution of diluted sample, since the transfer toward the outside of the solution of diluted sample occurs on the same upper side of the test tube in which the collection terminal is inserted, through the tubular transfer member which is directly connected fluidically to the hollow rod.

Furthermore, the provision of calibrated loop housings to collect the fecal sample allows to correctly quantify the fecal sample which is diluted into the diluting solution, suitably reducing the volume thereof for the purposes of occult blood tests. The collection terminal therefore acts both as a collection element proper, and also as a mean to quantify the fecal sample.

In one form of embodiment, the collection terminal comprises at least a collection body, which is made of sintered porous material which defines internal passage paths so as to obtain the passage ways. Moreover, advantageously, the porosity of the collection body also functions as a filtering diaphragm, reducing bacterial contamination of the analytical instrumentation, as well as preventing the passage of corpuscular material which can invalidate the analyses. The collection terminal, in this variant, functions both as a collection element proper, and as a mean to quantify the fecal sample, and also as a passage and filtration element of the diluted solution of fecal sample. In this variant it is therefore possible to filter the diluted solution using the collection terminal itself. In this way, therefore, it is not necessary to provide additional filtering components, thus simplifying the device and reducing the costs thereof.

In a variant, at the upper part, the collection body has an end with a pin, for the mechanical and fluidic connection, thanks to the porosity of the material, to the hollow rod.

In another variant, the collection body is made of a non-porous plastic material.

According to one form of embodiment of the invention, the hollow rod is provided with apertures which define the passage ways.

In a variant, at least one filter is provided, disposed downstream of the apertures along the passage paths of the diluting solution toward the tubular member.

In some variant solutions, the test tube is made of flexible material able to be deformed so as to determine a super-pressure in order to expel a desired aliquot of diluted solution through the tubular member

The present invention also concerns a method for taking, preparing and transferring fecal samples for the purposes of occult blood tests using at least a test tube which contains a diluting solution.

According to the present invention, the fecal sample is collected by means of a collection and transfer unit and is inserted inside the test tube, obtaining, from the suspension of the fecal sample collected in the diluting solution, a diluted solution contained in the test tube.

The method, once the fecal sample is inserted in the test tube, provides to close the test tube by means of a first stopper, to prepare the diluted solution and to transfer the diluted solution using a tubular transfer member which protrudes externally from the first stopper and which has a longitudinal cavity through which the diluted solution is transferred from inside the test tube toward the outside.

A hollow rod of the collection and transfer unit is axially aligned to the tubular member, protruding from the first stopper from the opposite side with respect to the tubular member.

The hollow rod has a first upper end coupled directly inside the longitudinal cavity of the tubular member, and is thus coupled inside the first stopper and connected fluidically to the tubular member so as to define a direct axial passage path of the diluted solution from the hollow rod through the tubular member and toward the outside.

According to the present invention, the hollow rod is used both to collect the fecal sample by means of a collection terminal comprising a collection body which axially has a plurality of calibrated loop housings to collect the fecal sample and provided at a second lower end of the hollow rod to be positioned inside the test tube, and to immerse the fecal sample present on the collection body into the diluting solution inside the test tube, and also to transfer a desired aliquot of the diluted solution thus obtained from the test tube through the hollow rod toward the tubular member associated at the upper part with the hollow rod.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some forms of embodiment, given as a non- restrictive example with reference to the attached drawings wherein:

- fig. 1 is a schematic view of the device for taking, preparing and transferring fecal samples according to the present invention;

- fig. 2 is a section of a part of the device in fig. 1 ;

- fig. 3 is an enlarged detail of a part of the device in fig. 1 ; - fig. 4 is an enlarged detail of another form of embodiment of the part in fig. 3;

- fig. 5 is a step of the method for taking, preparing and transferring fecal samples according to the present invention;

- figs. 6, 7, 8 are variants of use, in the same step of the method, of the present invention.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DESCRIPTION OF SOME FORMS OF EMBODIMENT

With reference to the attached drawings, a device 10 according to the present invention can be used for taking, preparing and transferring fecal samples, intended, in particular, to verify the presence of occult blood in feces.

The device 10, as shown in fig. 1, comprises a test tube 13, which can be made of flexible material so that it can be deformed manually in order to determine a desired super-pressure to cause its contents to exit toward the outside.

The test tube 13 has a shape and size such as to allow it to be handled by possible analysis devices, situated in the laboratories, without the need for a possible decanting of the fecal samples contained therein into subsequent and dedicated test tubes, thus reducing the risk of degrading the quality of the samples.

A diluting solution is already present in the test tube 13, and is used to dilute the fecal sample introduced therein, producing a diluted solution 37 of fecal sample which will subsequently be analyzed.

Moreover, the device 10 comprises a collection and transfer unit 12 able to be coupled and removably inserted into the test tube 13 through an upper aperture 16 thereof.

The collection and transfer unit 12, in its turn, comprises a first stopper 14 at the top able to cooperate with the upper aperture 16 of the test tube 13.

The first stopper 14 has a tubular member 18 through which a desired quantity of the diluted solution 37 is transferred toward the analytical instruments, dedicated or not, or in any case to deliver a desired aliquot of the diluted solution 37 on a suitable support which will be processed by the analytical instruments.

The tubular member 18 in this case is of a substantially conical shape, and protruding from a first external surface 14a of the first stopper 14 and has a transfer hole 28 to allow the diluted solution 37 contained inside the test tube 13 to exit therefrom. The tubular member 18 can also function as a handle to handle or transport the collection and transfer unit 12.

Moreover, the tubular member 18 defines, on a second internal surface 14b of the first stopper 14, a longitudinal cavity 1 1 axially aligned to the hole 28.

The first stopper 14 of the collection and transfer unit 12 also comprises a clamping collar 22 which juts out peripherally from the second lower surface 14b, with a shape and size mating with the upper aperture 16 of the test tube 13.

Along its external lateral surface, the collar 22 comprises an annular rib 24 able to achieve a same-shape coupling with a mating annular groove 26 made along the portion of internal wall of the test tube 13 in correspondence to the aperture 16 of the test tube 13. In this way, the annular rib 24 allows to attach the first stopper 14 to the test tube 13 by simple pressure.

The first stopper 14 is associated to a hollow rod or cannula 15, 1 15 which extends longitudinally from the second internal surface 14b of the first stopper 14.

The hollow rod 15, 1 15 has a through axial cavity 15a, for the passage of the diluted solution 37.

Moreover, the hollow rod 15, 1 15 is provided with a first end 27, which is able to couple inside the longitudinal cavity 1 1 defined by the tubular member 18. In this way, the fluidic connection is allowed between the hollow rod 15, 1 15 and the tubular member 18, so as to transfer the diluted solution 37 toward the outside of the test tube 13.

Moreover, the hollow rod 15, 1 15 has a second end 29 which defines a coupling portion 36 of a collection terminal 17, 1 17 for the fecal sample, which will be described in more detail hereafter.

The collection and transfer unit 12 also comprises a closing cap 19, which is connected to the first stopper 14 by means of a flexible rod 20. The rod 20 has a length and flexibility such as to be able to pass from a first external position to a second position above the tubular member 18, in order to allow the positioning of the closing cap 19 above the hole 28 of the tubular member 18, so as to close it.

The device 10 also comprises a second stopper 30, able to close the aperture 16 once the collection and transfer unit 12 is removed from the test tube 13. The second stopper 30 is connected, by means of an easily bendable connector 23, to the upper external edge of the test tube 13, in correspondence to the aperture 16.

The second stopper 30, similar in conformation to the first stopper 14, has a collar 21 with an annular rib 24a to cooperate with the annular groove 26 of the test tube 13. The second stopper 30 is used, once the connection and transfer unit 12 has been removed, to close the aperture 16 of the test tube 13 when the diluted solution 37 is inside it.

There is a measuring collimator 25 inside the test tube 13, which defines a progressive reduction in the passage section of the test tube 13, so as to cooperate with the collection terminal 17, 117 in order to remove from the latter a possible excess of fecal sample collected before it is immersed in the diluting solution present on the bottom of the test tube 13. In particular, the measuring collimator 25 comprises a wall 25 a, conical or truncated cone shaped, facing toward the bottom of the test tube 13, having a through hole 28a at its center through which the collection terminal 17, 1 17 and part of the hollow rod 15, 1 15 are inserted. The through hole 28a has a size coordinated to that of the collection terminal 17, 1 17, in such a way as to pass flush with the peripheral edges of the through hole 28, so as to eliminate any possible excess of fecal sample, which could invalidate the tests by causing false positives to occur.

The test tube 13, depending on requirements or needs, can provide a zone on its external surface where a suitable label with a bar code can be affixed, which will be used to trace the fecal sample collected.

As shown in fig. 3, a first form of embodiment of the collection terminal, indicated for convenience by the reference number 17, has a collection body 17a in this case oblong in shape and with an axial development, which has, along the surface, a plurality of calibrated collection loop housings 33 so as to correctly quantify the fecal sample collected, said loop housings 33 being able to be collimated, alternating with crests 32, in this case with an axially helical development, in order to collect the fecal sample, which occurs in an efficient way irrespective of how it is transferred. In the first form of embodiment of fig. 3, the collection body 17a is made of sintered porous material which, due to its porosity, internally defines a plurality of channels, openings or passage paths for the fluidic collection with the hollow rod 15, so as to make passage ways which allow the flow of the diluted solution 37 to be transferred toward the tubular member 18.

The collection body 17a comprises in its upper part an end with a pin 31 connecting in the coupling portion 36 of the second end 29 of the hollow rod 15. The end with a pin 31 therefore performs both the function as a passage for the diluted solution 37, thanks to its porosity, and also the function of mechanical connection with the rod 15.

The sintered porous material with which the collection terminal 17 is made, also allows to filter the diluted solution 37 which passes through it, obtaining a simplification of the assembly, since it avoids using specific dedicated filters normally used in known devices for sampling/analysis of fecal samples and thanks to which, normally, the passage of bacteria and corpuscular material toward the analytical instrumentation is reduced.

Fig. 4 shows a second form of embodiment of the collection terminal, indicated for convenience by the reference number 1 17, which is substantially equal to the form of embodiment in fig. 3, except for the material that makes up the collection body, indicated by reference number 1 17a, which is made of a non- porous material, such as a non-porous plastic material. In this solution, to allow the passage of the diluted solution 37 from inside the test tube 13 toward the inside of the hollow rod, indicated in this case by the reference number 1 15, apertures or slits 34, in this case longitudinal, though other conformations are not excluded, are provided in correspondence to the second end 29 of the hollow rod 1 15. Inside the axial cavity 15 of the hollow rod 1 15, and downstream of the apertures 34 along the exit path of the diluted solution 37, a standard type filter 35 is advantageously placed, used to filter the diluted solution 37 before it is sent for analysis, preventing the passage of bacteria and corpuscular material.

The transfer method which uses the device 10 of the present invention is described hereafter, with reference to figs. 5-8.

Once the fecal sample has been taken, using the collection terminal 17, 1 17, the latter is inserted inside the test tube 13 containing the diluting solution (fig. 5), closing the aperture 16 with the first stopper 14. The collection terminal 17, 1 17, before being immersed at least partly into the diluting liquid of the test tube 13, passes beyond the through hole 28a of the measuring collimator 25, thus removing any possible excess fecal material.

By immersing at least part of the fecal sample present on the collection terminal 17, 117 into the diluting solution, a diluted solution 37 is obtained, a art of which will be transferred, through the tubular member 18, to the outside, in the case of the variant in fig. 3, through the porous material that makes up the collection body 17a, and in the case of the variant in fig. 4, through the apertures 34 made through the hollow rod 1 15.

Fig. 6 shows a first variant in which the test tube 13 is ready for a dedicated analytical instrument. In this variant, in the transfer step, part of the diluted solution 37 is sent from the test tube 13 to the dedicated analytical instrument. In this step, with the test tube in a vertical position, and not upended, the tubular member 18 is connected to a standard mechanical terminal provided on the dedicated analytical instrument, by means of which the diluted solution 37 is sucked into the suitable measuring chamber of the instrument, following the path as described above.

Fig. 7 provides a variant in which, instead of automatic suction, manual methods are used, such as lateral flow or immuno-chromatographs, and the test tube 13 is ready for analyses on a slide. In this case, by pressing lightly on the upended test tube 13 a slight overpressure is created to expel some drops of diluted solution 37 in a measured way, which are deposited on a suitable support which will be processed by the chosen analysis device.

Fig. 8 provides another variant in which the test tube 13 is ready to cooperate with a vacutainer test tube 38 of the known type and standardized shape for non- dedicated open instruments, and in which, thanks to the pointed shape of the tubular member 18, the stopper of the vacutainer test tube 38 is easily perforated. Once the tubular member 18 is inserted, the method proceeds as described for fig. 7, introducing a desired aliquot of diluted solution 37 into the vacutainer test tube 38, which will then be inserted inside the non-dedicated instrument of the clinical chemical type.

Claims

1. Device for taking, preparing and transferring fecal samples for occult blood test, comprising at least a test tube (13) to contain a diluting solution and a collection and transfer unit (12) for the fecal sample to be inserted inside the test tube (13) so as to obtain, from the suspension of the fecal sample collected in the diluting solution, a diluted solution (37) of said fecal sample contained inside the test tube (13), characterized in that said collection and transfer unit (12) comprises:

- a first stopper (14) to close said test tube (13),

- a tubular transfer member (18) which protrudes externally from said first stopper (14) and which has a longitudinal cavity (1 1) through which said diluted solution (37) is transferred from inside the test tube (13) toward the outside,

- a hollow rod (15, 1 15) which protrudes from said first stopper (14) from the opposite side with respect to the tubular member (18) and able to be inserted inside said test tube (13), which hollow rod (15) is axially aligned to the tubular member (18) and has:

- a first upper end (27) coupled directly inside the longitudinal cavity (1 1) of the tubular member (18), thus being coupled inside said first stopper (14) and fluidically connected to said tubular member (18) so as to define a direct axial passage way of the diluted solution (37) from the hollow rod (1 ) through said tubular member (18) and toward the outside,

- a second lower end (29) to be positioned inside the test tube (13) and bearing at least a collection terminal (17, 1 17) for the fecal sample comprising a collection body (17a, 1 17a) which axially has a plurality of calibrated loop housings (33) for collecting the fecal sample,

passage ways being provided to put the inside of the test tube (13) in communication with the inside of said hollow rod (15), so as to allow the diluted solution (37) to flow from inside said test tube (13) toward said tubular member (18), through said hollow rod (15).

2. Device as in claim 1, characterized in that said collection loop housings (33) have axially a helical development.

3. Device as in claim 1 or 2, characterized in that said collection terminal (17) comprises at least a collection body (17a), which is made of sintered porous material which defines internal passage paths so as to obtain said passage ways.

4. Device as in claim 3, characterized in that at the upper part said collection body (17a) has an end with a pin (31) for the mechanical and fluidic connection to said hollow rod (15).

5. Device as in claim 1 or 2, characterized in that said hollow rod (1 15) is provided with apertures (34) which define said passage ways.

6. Device as in claim 5, characterized in that it comprises at least a filter (35) disposed downstream of said apertures (34) along the passage path of the diluting solution (37) toward the tubular member (18).

7. Device as in any claim hereinbefore, characterized in that said test tube

(13) is made of flexible material able to be deformed so as to determine a super- pressure in order to expel a desired aliquot of diluted solution (37) through said tubular member (18).

8. Method for taking, preparing and transferring fecal samples for occult blood test, using at least a test tube (13) which contains a diluting solution in which the fecal sample is collected by means of a collection and transfer unit (12) and is inserted inside said test tube (13), obtaining, from the suspension of the fecal sample contained in the diluting solution, a diluted solution (37) contained in the test tube (13), characterized in that, once the fecal sample is inserted in the test tube (13)^ it provides to close the test tube (13) by means of a first stopper (14), to prepare the diluted solution (37) and transfer the diluted solution (37) using a tubular transfer member (18) which protrudes externally from said first stopper

(14) and which has a longitudinal cavity (1 1) through which to transfer said diluted solution (37) from inside the test tube (13) toward the outside, wherein a hollow rod (15, 1 15) of the collection and transfer unit (12) is axially aligned to the tubular member (18), protruding from said first stopper (14) from the opposite side with respect to the tubular member (18) and has a first upper end (27) coupled directly inside the longitudinal cavity (1 1) of the tubular member (18), thus being coupled inside said first stopper (14) and connected fluidically to said tubular member (18) so as to define a direct axial passage path of the diluted solution (37) from the hollow rod (15) through said tubular member (18) and toward the outside, said hollow rod (15) being used both for collecting the fecal sample by means of a collection terminal (17, 1 17) comprising a collection body (17a, 117a) which axially has a plurality of calibrated loop housings (33) for collecting the fecal sample and provided with a second lower end (29) of the hollow rod (15) to be positioned inside the test tube (13), both to immerse the fecal sample present on the collection body (17a, 1 17a) into the diluting solution inside the test tube (13), and also to transfer a desired aliquot of the diluted solution (37) thus obtained from the test tube (13) through said hollow rod (15, 1 15) toward the tubular member (18) associated at the upper part with said hollow rod (15, 1 15).