Reagent Package

The present invention concerns a procedure for keeping and for taking into use an analytic reagent or another substance used in analyses.

Technically manufactured analytical reagents, and standard and control materials for use in analyses, are usually packed in glass bottles, ampoules or plastic bottles, either in liquid or solid form. In most instances, the person making the analysis must manually dilute and mix a plurality of reagents for each single analysis. As a consequence, making an analysis requires professional skill and good understanding of the chemistry involved. A drawback of known procedures is that the room temperature, evaporation during various handling phases and microbiological contamination may impair the keeping quality of the reagents and other materials that are used so that they are usable during a brief period only. Thus, of the total reagent consumption only a fraction is actually used in analysis.

The object of the invention is to provide a procedure which is free of the drawbacks mentioned. The invention is characterized in that the substance to be used in analysis is hermetically packed in a bag, or sachet, serving as a storage container and having at least one flexible wall. Use of the substance is accomplished by forming a discharging aperture in the sachet such that the sachet is connected through its discharging aperture to the apparatus using the substance, for instance an analyser, with an outward substantially gas-tight connection. Substance is drawn from the sachet into said apparatus in one or several steps so that the sachet collapses in connection with the discharging.

By using the invention, there is no evaporation of the substance to be used in analysis before nor after it is taken into use. Thereby the concentration of the substance is kept constant at all times until the sachet connected to the analyser has been totally emptied. Thus, the contents of the sachet may be utilized in their entirety, independent of the quantity of substance that has been packed in the sachet. A further consequence of the sachet's gas tightness is that the package is completely sterile and that no contamination whatsoever can occur.

Thanks to the flexibility and collapsibility of the sachet, one sachet size may be used to package even greatly varying substance quantities. In most instances the substance to be packed in the sachets is liquid, but the sachet is equally suitable as a package for gaseous or solid substances. Packaging of solid substance may be achieved when the substance is unstable as a solution but stable in solid form, and conversion of the solid substance to a solution is then effected in the sachet before the substance is used.

The invention is particularly applicable to automatic analysers, for instance in an analyser of the type disclosed in the Finnish Pat. No. 57850. When using such analysers, in conjunction with the applicants' invention, one is spared all the awkward and exacting manual work, since the sachet containing reagent can be so connected to the analyser that the analyser itself performs the extraction of the substance from the sachet, as well as all subsequent operations.

The invention also concerns a reagent package intended for application of the procedure presented. The package is characterized in that it consists of a gas-tight sachet or of a combination of several sachets, where the sachet comprises at least one flexible wall and a blank for the forming of a discharging aperture, so that the sachet can be connected by an outward substantially gas-tight connection to an analyser or equivalent apparatus and can be emptied by suction so that the sachet will collapse in connection with such emptying.

The sachet constituting the reagent package of the invention is preferably substantially flat and comprises two opposed, flexible walls, which are urged against each other as the sachet is emptied. The said walls may consist of a lamination formed of a metal foil and a plastic film on its inside, and the plastic may have seams around the edges of the sachet closing the sachet, these seams being established by a heat seaming process.

Establishing the discharging aperture may be accomplished by a flexible tube extending into the sachet and which tube is hermetically closed at the packaging step. On being opened, the flexible tube will then serve as discharge aperture. Furthermore, the flexible tube may at the packaging step serve as a passage by which the sachet, previously formed to be gas-tight, is filled. The flexible tube is preferably made of the same plastic material as that with which the sachet is seamed, and hermetical closing of the sachet may in that case be accomplished by heat seaming.

The sachet may, instead of said flexible tube, comprise a bar-like body attached to an edge of the sachet by heating seaming and containing a passage extending to the opening of the bag and hermetically sealed at the packaging step and which can be opened for forming a discharge aperture. The bar-like body likewise preferably consists of plastic and has been sealed to the plastic material that is used in seaming the edges of the sachet.

The reagent package of the invention may consist not only of a single sachet but also of a sachet combination with a plurality of sachets attached to each other by their edges and with the different sachets preferably containing different reagents. Such a combination of sachets, connectable as such to an analyser, may contain all the reagents and other substances needed in a given analysis. The substance quantities contained in different sachets may then be quite radically different, but it is possible in spite of this to make the sachets in the combination of equal perimeters. On the other hand, of course, the sachets may be different in size, provided that the blanks provided to form the discharge apertures are so disposed that the combination is connectable as it is to the connecting conduits of the analyser.

The invention is described in the following in greater detail with the aid of examples with reference to the attached drawing, wherein:

FIG. 1 presents the sachet, fitted with a flexible tube, constituting a reagent package according to the invention,

FIG. 2 shows the section II--II from FIG. 1,

FIG. 3 presents, sectioned, the seam area on the edge of the sachet of FIG. 1,

FIG. 4 presents a reagent package according to the invention consisting of two sachets, attached to each other, and each provided with a passage through which the sachet may be filled or emptied,

FIG. 5 shows the section V--V from FIG. 4,

FIG. 6 shows the section VI--VI from FIG. 4,

FIG. 7 shows the passage belonging to a single sachet, presented as section VII--VII from FIG. 4,

FIG. 8 presents the end of a connecting conduit belonging to the analyser and connectable to the passage of FIG. 7,

FIG. 9 displays schematically a reagent package according to the invention, consisting of a sachet combination comprising ten sachets, connected with an analyser through two connector banks and conduits departing therefrom.

FIG. 10 displays, in elevational view, the connector bank connected by conduits to the analyser and which is attachable to a reagent package according to the invention comprising a plurality of sachets side by side,

FIG. 11 shows the connector bank of FIG. 10, viewed from the front,

FIG. 12 presents in elevational view a reagent package according to the invention, comprising five sachets side by side, to which the connector bank of FIG. 10 is connectable,

FIG. 13 displays part of the reagent package of FIG. 12, viewed from the front, and

FIG. 14 shows the connector bank of FIG. 10 and the reagent package of FIG. 12 connected to each other.

In FIGS. 1-3 is depicted a gas-tight sachet 1, constituting the reagent package of the invention. The sachet 1 is substantially flat and comprises two opposed, flexible walls 2, which have been seamed on the edges of the sachet to adhere to each other and form seams 3. The walls 2 consist of three-ply lamination having as its innermost ply 4 a film of polyethylene, the next ply 5 being an aluminium foil and the outermost ply 6, a polyamide film. The polyethylene has the task to form the seams 3 on the edes of the sachet, which have been formed by heat-seaming the opposed polyethylene films 4 to each other, and furthermore the polyethylene film is a suitable inert material to be used for the inside surface of the sachet 1 which comes into immediate contact with the material packed in the sachet. The purpose of the aluminum foil 5 over the polyethylene film is to endow the sachet 1 with requisite gas-tightness, and with the aid of the outermost polyamide film 6, a tough and mechanically durable surface of the sachet has been produced. A flexible tube 7 leading into the interior of the sachet has been affixed to the sachet 1 by seaming, and this flexible tube is hermetically closed until the substance packed in the sachet is used.

At the packaging step, an analytic reagent or another substance for use in analysis is enclosed in the sachet 1. The reagent or substance may be a standard or control material, which in most instances is liquid but may also be in solid or gaseous form. A liquid reagent is preferably, when being packaged, free of foreign gases such as oxygen which might impair the keeping quality of the reagent or interfere with the analysis. The packaging may be accomplished by filling previously seamed sachet 1 through the flexible tube 7, whereafter the flexible tube 7 is sealed. A possible alternative is to place the substance in the sachet while the sachet is still partly unseamed, and then to close the sachet by finally seaming the edges closed.

To use the substance packed in the sachet 1 the flexible tube 7 is opened and the sachet is connected to the apparatus using the substance, such as an analyser, by this tube with a connection which is outward substantially gas-tight. The substance may then be drawn by suction from the sachet 1 into the apparatus in one or several steps so that the sachet will collapse in connection with emptying. Thanks to the gas-tightness of the sachet and of the connection between it and the analyser, even prolonged intervals may be allowed between discharging steps without incurring any change of the substance in the sachet.

In FIGS. 4-7 is depicted a reagent package consisting of two sachets 1 placed side by side and attached to each other. The sachets are equivalent to the embodiment of FIGS. 1-3 described above, as regards the material of their walls 2 and their edge seams 3. However, an essential difference is that the sachets comprise no flexible tubes extending into their interior. Instead, the sachets 1 are provided with a common, bar-like polyethylene body 8 affixed to the end of the sachets by seaming. In the body 8, passages 9 have been formed which are hermetically closed with a polyethylene film 10 seamed fast to the edge of the body at the packaging step.

Use of the package shown in FIGS. 4-7 takes place by hermetically connecting the sachets 1 to the analyzer by the passages 9 and by connecting conduits 11,. In FIG. 8 is shown the end of a connecting conduit 11 and a tubular mandrel 12 attached thereto, which pierces the film 10 on the mouth of the passage 9 and thereafter connects the passage 9 and the connecting conduit 11.

The package according to FIGS. 4-7, comprising two sachets, is the simplest possible combination package, in which the sachets may contain different reagents used in the same context. It is thus not intended to separate the sachets at any stage: the package is in contrast connected to the analyser as one single entity.

In FIG. 9 is depicted a combination package 14 connected by conduits 11 to an analyser 13, this combination package consisting of ten sachets 1, denoted with A to J in the figure. The sachets may be constructed as in FIGS. 4-7 and they may contain all the reagents and other substances needed to carry out a given analysis. Two bar-like connector banks 15 having on their ends projections 16, have been used to connect the package 14 to the analyzer 13. The passages 9 in the bar-like bodies 8 of the package 14, which lead into the sachets 1, are slightly offset from the centre-lines of the sachets, this offset being larger on one side of the package than on the other. The connector banks 15 have been provided with mandrels pushing into the passages 9, which mandrels may have the shape shown in FIG. 8 (reference numeral 12) and are located on the connector banks in register with the passages. Due to the location of the projections 16 and the passages 9 and mandrels on the connector banks 15, each connector is only connectable in one given position on one given side of the package 14. Thus, each conduit 11 going to the analyser 13 can only become connected with one predetermined sachet 1 in the package 14 and thus no possibility of misconnection exists.

In FIGS. 10-14 has been presented a further embodiment of the combination package 14 of the invention, connectable to the analyser 13 through a connector bank 15. The connector bank 15, depicted in FIGS. 10 and 11, consists of an elongated rod with which the conduits 11 going to the analyser 13 connect and which carries mandrels 12, which enter the package 14, on the end of each conduit. The end of the connector 15 has been connected with a member 17 shaped like an inverted letter U and provided with a projecting pin 18. The combination package 14, presented in FIGS. 12 and 14, consists of five sachets 1 side by side, these sachets being indicated with A to E, and of a bar-like member 8, as described above, provided with passages 9 leading into the sachets. On the end of the package 14 has been affixed a plate-like member 19 with a hole 20 corresponding to the pin 18 belonging to the connector 15. When attaching the connector 15 and package 14 to each other as shown in FIG. 14, the members 17 and 19 are first placed against each other so that the pin 18 enters the hole 20. Next, the bar-shaped part of the connector 15, which is movable with reference to the member 17, is pressed against the bar-like body 8 of the package 14 so that the mandrels 12 enter the passages 9 leading into the sachets 1. It is essential in the design solution of FIGS. 10-14 that the attachment of the package 14 and the connector bank 15 is conditional on compatibility between the pin 18 and hole 20. In a case in which a great variety of different combination packages are to be connected over connector banks to the same analyzer, it is possible to make sure that each type of package can only be connected to a given connector bank by varying the location of the pin 18 and hole 20 on the members 17 and 19, thereby eliminating the possibility of missconnection.

Preliminary tests carried out with packages according to the invention have demonstrated that the losses by evaporation from the package, per unit area, are only about 0.2 to 0.3% of the losses taking place from conventional reagent packages of prior art.

It is obvious to a person skilled in the art that various embodiments of the invention are not confined to the examples presented and may instead vary within the scope of the claims following below.