WO1985005048A1

WO1985005048A1 - A device for a quick and automatic removal of a liquid phase from a solid phase inside a container, in particular in a test tube

Info

Publication number: WO1985005048A1
Application number: PCT/IT1985/000003
Authority: WO
Inventors: Paolo Giuseppe Campolo
Original assignee: Paolo Giuseppe Campolo
Priority date: 1984-05-09
Filing date: 1985-04-26
Publication date: 1985-11-21
Also published as: EP0213131A1; IT8448155A0; AU4355685A; IT1199121B

Abstract

The device (2) consists in a closing body (3) with a roomy inner space (3') in the upper part thereof, and the lower cupling part thereof being provided with a tight pitch thread (7). The diameter (D) of the inner space (3') is greater than the diameter (d) of the lower part for the cupling with the test tube (1). A strongly compressable means (5) being highly absorbent and wrapped up in a thin piece of paper (4) is inserted in space (3') and soaks - once the test tube is placed upside down - with the whole liquid phase contained therein. Radioactive or infectious contaminations, due to direct contact or volatilization, for the operator or the ambient are excluded.

Description

"A DEVTCE FOR A QUICK AND AUTOMATIC REMOVAL OF A LIQUID PEASE FROM A SOLID PHASE INSIDE A CONTAINER, IN PARTICULAR IN A TEST TUBS".

DESCRIPTION

The present invention concerns a device for a quick and automatic removal of a liquid phase from a solid phase, already separated, inside a container, in particular inside a test tube.

In the laboratories it is necessary to use radio- activen infectious or, in any case, poisonous reactive substances that are to be added, in a test tube, to the serum drawn from a patient, so as to perform on said serum the wanted analysis.

As it i s already known, thes e radioactive, inf ecti ous or in any case p ois onous reactive subs tnces are used in liquid phase, and the same contain, among others , molecules of antibodies as well as molecules of antigens , having a shape corresponding to the one of the molecules of antibodies and antigens that are to be quantified in the serum . One example for this kind of analysis are the radio-immunology test and some tests for enzyme-immunology . These tests are both based on two methods that have in common the final f ormation of a liquid phas e and a solid phase that must be separated for obtaining reliable results.

In the first method, a first specific antibody is used against the antigen to be quantified, and a second antibody is used, specific for the determinant Fc of the firsi antibody. Said second specific antobody has been made quantifiable by means of an incorporated radioactive atom, or by means of an enzyme linked to said antibody by means of a covalent link.

It should be kept in mind that said first antibodies, specific against the antigen to be quantified, as well as said second antibody, specific for the determinant Fc of said first antibodies, as well as said antig-ens made quantifiable by means of an incorporated radioactive atom or by an enzyme, are always used in a number exceeding the one of the antigens presumably contained in the serum available.

In the first case, once the serum and the liquid solutions, containing all necessary substances, are let in the test tube, each specific antibody gets linked to the corresponding antigen forming an assembly that, partially, is still soluble in the liquid phase. Said second antobody in turn gets linked to the determinant Fc of the first antibody, already linked to the antigen, thus making the three molecules insoluble in the liquid phase and making them precipitate as a single assembly.

In such conditions and after some time, usually some hour, a precipitate is formed on the bottom of the test tube. When the precipitation is ended, all insoluble assemblies will have deposited on the ground, containing the antibody made quantifiable by a radioactive atom or by an enzyme, thus allowing the quantification of the antigen contained in the serum in an unknown concentration, by means of a calibration curve.

Obviously, all those molecules that are still soluble, i.e. all the antigens present in the serum and of a different kind than the one of the antigens to be quantified, as well as all said first antibodies specific against the antigens to be quantified, and all said second antibodies made quantifiable by a radioactive, incorporated atom or by an enzyme linked to the same by a covalent link, that will prove to be in excess with respect to the antigens to be quantified present in the quantity of available serum, remain in the liquid phase. In the second case, the antigen made quantifiable by a radioactive atom or by an enzyme, will get linked to the antigen to quantify in the solution consisting in the reactives and the serum. Also in this case assemblies insoluble in the liquid phase are obtained, due to the same above mentioned principle. In this case the number of antigens made quantifiable and that will be found in the solid phase is inversely proportional to the number of antigens to quantify; however, with the auxilium of a calibration curve it is possible to quantify the number of antigens contained in the serum in an unknown concentration.

Also in this case, once the precipitation is completed, all the antigens made quantifiable by a radioactive atom or an enzyme and that are exceeding the presumed number of antigens to quantify contained in the available serum concentration remain in the liquid phase.

For accelerating the separation of the liquid phase from the solid phase, the test tube will undergo, as it is known, centrifugation. Thus the separation of the liquid phase from the solid phase will be quickly obtained and now it will be necessary to remove said liquid phase from the test tube so that the test tube, together with the solid phase, may undergo further analysis operations.

Actually, it is known to the art that the removal of the liquid phase takes place by suction, e.g. by means of a syringe or a pipette, or also simply by decantation, pouring the liquid into a suitable collection container. The test tube - once the analysis of the solid phase is completed - will be thrown in a suitable collection container.

All these operations take about great disadvantages that may influence the result of the analysis as well as the personnel working in the laboratory.

First of all, the suction of the liquid phase may cause interferences due to the instrument, e.g. a syringe or a pipette put inside the test tube, which instrument may cause a turbulence by depression onto the solid phase and suck a part thereof, thus altering the results of the analysis.

Furthermore, it is extremely dangerous that the handling of an open test tube, containing just those above mentioned radioactive, infectious or, in any case, poisonous substances, may cause the outcome and, therefore, the direct contact with the o perator and the ambient. Also the suction by means of a syringe or a pipette means an evident danger rate for the operator. The removal of the liquid from the test tube by means of direct decantation into a collection container is obviously the most dangerous because it spreads in the container - as it is not hold back in any way - or it can also get out of the test tube, due to the operator's inattention. The danger of the volatilization of some reactive substances and, most of all, the fact that this operation must always be repeated by the laboratory's operators, must be added. Finally, it should be kept in mind that, very oftenly, the liquid is directly poured in the discharge, with a highdiffusion and contagion possibility for others.

It is the aim of the present invention to solve all above mentioned inconveniences realizing a device to be applied to a container or, in particular, to a test tube, that allows the removal of the liquid phase from the solid phase inside said container, thus obtaining a hermetic and definite isolation from the outside and allowing to throw away the container with the content thereof,

The aim is reached by means of the present in vention realizing for a container, in particular for a test tube, a device in the shape of an air tight closing, characterized in that inside said closing an absorbing means is incorporated, the absorbing capacity and the volume thereof being such as to quickly suck - once the container or the test tube is set upside down - at least the whole liquid phase contained therein.

The object of the present invention will be described hereinbelow relating to a preferred embodiment shown, for exemplifying and not limiting purposes, in the attached drawings, in which the figures show:

figure 1, a view of the whole of a test tube with a hermetic closing device according to the present invention; figure 2, a section, in an enlarged scale, of a test tube with a device according to figure 1; figure 3, an exploded view of the test tube, of the device and of the incorporated absorbing means; figure 4, a cross section of the device; figure 5, a front view of the test tube of figure 1, with the reactive inside, that now requests centrifugation; figure 6, a view similar to the one of figure 5, with the reactive inside, that does not request centrifugation; figures 7 and 8, views similar to the ones of figures 5 and β, with the test tubes upside down and the liquid phase absorbed by the device according to the present invention.

The device according to the present invention can be seen in figures 2 and 3 and is shown with 2. Said device consists in a closing body 3 made of synthetic material, preferably of cylindric shape, being hollow inside and upwardly provided with a roomy space 3'. Below space 3', the closing body shows a part for the coupling with the test tube 1, being of a diameter d smaller than the diameter D of said space and being outwardly provided with a very tight pitch thread 7. The diameter d of the lower part of the closing body 3 is sensitively equal to the inner diameter of the test tube - or of any other container - so as to penetrate the same, after a light pressure, due to the elasticity of the material said body is made of. The tight pitch thread contributes to the air tight closing. Inside the closing body 3

Inside the closing body 3, an absorbing means 5 is inserted, of a clearly compressable feature and of a clear absorbing capacity, of cylindric shape and with a diameter equal to the diameter D of the roomy space 3' in the closing body 3. The absorbing means, having a cylindric shape, is wrapped up, for containing the same and for facilitating the insertion thereof, in a thin piece of paper 4. After having inserted, as above described, the absorbing means in body 3, at height with the lower peripheral outline of the coupling part, the upper part of the means, mainly in volume, gets elastically expanded in upper room 3', while in the inside of the coupling part only one minimum portion of said means is compressed.

The removal of the liquid phase from the solid phase therefore takes place by simply placing the test tube 1 upside down and very quickly, due to the high absorbing capacity of the employed means. The capacity of the space inside the closing body allows to keep the necessary part of liquid, exploiting the roominess thereof and limiting the depth of the coupling part of closing body 3 and of that part of the .absorbing means present therein, to the sole measure required for the air tight closing of the test tube and preventing an untimely contact with the liquid phase. The test tube may therefore undergo the next analysis without having to take off the liquid phase, and this eliminates any contamination risk for the operator by direct contact, "by volatilization as well as the diffusion of the liquid phase in the ambient or in the collection containers.

Figures 5 and 6 are examples of how the liquid phase may be removed from the solid phase in a container, or test tube, when the same shall undergo centrifugation as well as when centrifugation is not requested.

From figure 5 it can be seen how the antigens AT, the antibodies AC specific against the antigens and the antibodies AR specific for the determinant Fc of the first antibody and made quantifiable by a radioactive atom or by an enzyme, have got linked and are precipitating to the ground of the test tube, where all the solid phase FS that has been formed with deposit. Once the centrifugation has ended, the test tube (figure 7) will be placed upside down and the solid phase will stick to the ground and all the liquid phase FL will be sucked by device 2 according to the present invention.

However, test tubes for radio-immunologic determinations (known as "coated tubes") are well known, in which the first antibody AC specific against the antigen is already linked to the test tube. Such a test tube is shown in figure 6 and, in this case, it is unnecessary for the same to undergo a centrifugation for the separation of the two phases. It is in any case necessary to remove the liquid phase from the test tube and also in this case said operation may be eliminated due to the device according to the present invention (figure 8).

The object of the present invention has been described and illustrated relating to a preferred embodiment. It is obvious that it will be possible to perform modifications in dispositions, proportions and dimensions, without therefore going out of the limits of the present invention.

Claims

1. A device for a quick and automatic removal of a liquid phase from a solid phase, being already separated, inside a container, in particular a test tube, said device (2) being shaped as an air tight closing body (3), characterized in that inside said closing body an absorbinc means (5) is incorporated, the absorbing capacity and the volume thereof being such as to quickly assiime, once the container or test tube is set upside down, at least the whole liquid phase contained therein.

2. A device according to claim 1, characterized in that the closing body (3) is inwardly hollow and upwardly provided with a roomy space (3') with a diameter (D) greater than diameter (d) of a lower part for the coupling in test tube (1).

3. A device according to claim 2, characterised in that said lower part for the coupling with the test tube (1) is provided with a very tight pitch thread (7).

4. A device according to claim 2, characterized in that inside said closing body (3) a clearly compressable absorbing means (5) is inserted, being at height with the peripheral outline of the coupling part.

5. A device according to claim 4, characterized in that said absorbing means (5) is wrapped up in a piece of paper (4). o A device according to claim 2, characterized in that the quantity of liquid phase (FL) present in test tube (1) will be absorbed and kept, for the maximum part thereof, inside a space (3') being very roomy, while the depth of the coupling part of the closing body (3) and of that portion of absorbing means present therein, is limited to the sole necessary one fro guaranteing the air tight closing of the test tube.