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Description  |
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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.
BRIEF DESCRIPTION OF THE DRAWING
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.
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