GB2295892A - Device for visual observation of chemical reactions - Google Patents

Abstract

Visual inspection of chemical reactions e.g. for agglomeration, precipitation, sedimentation or especially colour change is effected using a device comprising a chamber at least partially defined by an elastic/flexible sheet or plate such that manual flexing of the sheet or plate effects mixing of the reagents in the chamber with subsequent visual observation of typically a colour change.

Description

TITLE OF THE INVENTION A TESTING METHOD FOR VISUAL INSPECTION OF CHEMICAL REACTIONS BY MIXTURE, AND A DEVICE THEREOF BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a testing method for visual inspection of chemical reactions resulting from the mixture of minute amounts of reagents and samples, and to a device used in association of that method. It is especially useful when used in laboratories because it is not only simple and safe in usage but also allows a rapid, visual determination of test results (mixture, aggregation, coloration, precipitation, sedimentation, and so on) at the sites where the reactions are allowed to occur by mixture.Moreover, with this method, it is possible to store the test results by pasting them onto recording forms, which not only allows long-term storage but also requires no significant space, and thus to dispense with the necessity of disposal of liquid wastes.

Prior Art With conventional methods, analysis, fractionation and assay based on chemical reactions such as mixture, coloration, aggregation, precipitation (sedimentation), and so on have been achieved, as shown in Japanese Utility Model Laid Open No. 62-47967, using test-tubes or microplates in which samples (specimens) and chemicals (reagents) are to be placed, and the mixtures must be mechanically vibrated or shaken to obtain desired results.

On the other hand, discharging of liquid wastes without proper treatment as was often done previously, has recently become unacceptable. When incineration is employed for the treatment, there have been accidents in association with the breakage of furnaces as a result of high temperature heating. When grinding is used for the treatment, toxic substances may be released in air, and indeed this has caused disasters in which people are infected with biological pollutants. Furthermore, for the tests repeated incessantly in laboratories, clinical test units and research institutes, the cost for purchase of starting materials and disposal of used materials has added up considerably every year, which encourages the development of a method based on ultra micro- analysis.

Thus, the present inventors had been repeating experiments with a view to find a method that would allow them to overcome the previous problems. As a result, they found that, when capillary action between two plates closely apposed, and the elasticity of those plates are put into a harmonious operation, even usage of minute amounts of materials will readily produce the same results as the method dependent on the usage of test-tubes that require more abundant materials.

The method for visual inspection of chemical reactions by mixture provided by the present invention is characterized with a chamber attached to a thin elastic base plate, which is for mixing a reagent(s) and sample(s), and allows the inspection from outside of the events inside.

The method consists of placing the reagent and material in the chamber, and mixing them by bending repeatedly the plate assembly in one way and the other, while watching the events in the chamber from outside so as to achieve a diagnosis of the reaction inside (Claim 1).

Further, the device used in association with the present method is characterized with a plurality of chambers attached to the thin elastic base plate, into which a reagent(s) and/or sample(s) can be introduced (injected) from outside, and allows one not only to observe from outside parts or the whole of the chambers' interior, but also to place a desired reagent(s) prior to mixture (Claim 2).

The method is further characterized by laying a plate strip(s) over the thin base plate, attaching firmly a desired spot(s) of the plate strip to the underlying base plate, and making at least either of the plate strip or the base plate transparent (Claim 5).

SUMMARY OF THE INVENTION The present invention provides a method for visually inspecting chemical reactions taking place as a result of mixture, and a device to be used in association. The method only requires the usage of very minute amounts of reagents and samples, is simple and safe in practice, allows a sufficiently rapid visual inspection of the reactions for diagnosis to be made at the site, makes it possible to readily store the test results, and dispenses with the disposal of liquid wastes. The device for the method is characterized with a plurality of chambers 3 attached to a thin elastic base plate 1, in which a desired reagent(s) 8 has been placed, into which a sample(s) can be introduced from outside, and parts or the whole of whose interior is visible from outside.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of the system of Fig. 2 with the individual parts disintegrated.

Fig. 2 is a top view of the system composed of three parts: a base plate, a cover and plate strips Fig. 3 is a perspective view of the system of Fig. 4 with the individual parts disintegrated.

Fig. 4 is a top view of the system composed of two parts: a base plate and a cover.

Fig. 5 is a top view of the system used for colorimetric analysis.

Fig. 6 is a top view of the system used for specifying blood types.

Fig. 7 is a top view of the system in which three reagents can be independently introduced into a mixing chamber.

Fig. 8 is a top view of the system in which pieces of absorbent filters or spacers are inserted.

Fig. 9 is a top view of the system in which a plurality of reagents can be introduced after being mixed or independently into a mixing chamber.

Fig. 10 is a top view of the system used for special tests.

Fig. 11 is an end view of a plate strip which has been given a bending disposition.

Fig. 12 is an end view of the assembly composed of a plate strip and thin base plate which have been given a bending disposition.

DESCRIPTION OF THE PREFERRED EXAMPLES The examples of the device of the present invention will be given below with reference to Figures.

EXAMPLE 1 Figures 1 and 2 illustrate a system in which punched-out windows are formed in a thin base plate, and the windows are closed from both sides with a cover and plate strips to form chambers. The rectangular thin base plate 1 made of a synthetic resin has an area of 5.5cm x 9.0cm and a thickness of 0.2mm. The area and thickness of the plate can be varied as appropriate depending on the objects to be tested or the number of the objects. Any materials are applicable for the plate as long as they have a sufficient elasticity to allow repeated bending (flexion and extension). For example, a thin plate made of a synthetic resin is convenient for the purpose, and water-proof paper coated with a synthetic resin, metal thin plate, and silicon-coated plate are also applicable.The equilateral windows 2 of the thin base plate 1 are to provide mixing chambers 3, and each has a notch 5 semicircular in form on its top side which works as an inlet 4 for samples. The area of the window is 1.2cm x 1.2cm. In the example illustrated in the figure, the windows 2 count two, but they may be prepared as appropriate in accordance with the number of samples.

A covering member 6 is for closing the back side of the windows 2 of the thin base plate 1. The cover can be made of any material and does not require any elasticity or flexibility of its material, as long as the material complies with the repeated bending of the thin base plate 1.

The cover 6 is firmly stuck to the thin base plate 1 so that the windows 2 are completely sealed. The cover 6 can be made of a transparent synthetic resin, a metal thin plate, or any other material with any color of preference.

Plate strips 7 are for closing the front side of the windows 2 of'the thin base plate 1. The plate strip is larger by about lcm for all sides than the window 2 and stuck to the latter so firmly that the front side of the window is closely sealed. Like the cover 6, the plate strip 7 can be made of any material regardless whether or not it has a sufficient elasticity or flexibility, as long as it does not interfere completely with the repeated bending of the thin base plate 1.

Further, the plate strip 7 can be made of a transparent synthetic resin, a metal thin plate, or any other material with any color of preference. However, in order that events inside can be seen from outside for diagnosis, at least either the plate strip 7 or the cover 6 should be made of a material that may allow a visual inspection of the interior from outside.

When the window 2 of the thin base plate 1 is closed posteriorly with the cover 6 and anteriorly with the plate strip 7, a chamber for mixture 3 is formed in the space of the window 2. However, the notch formed on the top side of the window 2 remains open, to act as an inlet 4 for samples, and this allows the introduction of samples into the mixing chamber 3.

A reagent 8 may be placed prior to mixture in the mixing chamber 3 depending on the sample to be tested. It may be used neat or after being soaked in a medium such as latex. The reagent may be completely fixed to a certain spot or allowed to move freely in the chamber 3. The reagent, instead of having been placed in the chamber, may be introduced together with the sample into the chamber when in use, depending on the sample to be tested.

It is worthy of mention that the plate strip 7 and the cover 6 should be previously given a bending disposition to opposite ways each other so that the introduction of reagents and samples into the chamber 3, and their mixture may be facilitated.

EXAMPLE 2 Figures 3 and 4 illustrates an example of the present invention in which plate strips are laid over a thin base plate and stuck to the latter at their desired spots.

The rectangular thin base plate 1 made of a synthetic resin has an area of 5.5cm x 9.0cm and a thickness of O.lmm, but its area and thickness may be varied as appropriate according to the objects to be tested and to their numbers.

Any materials can be applicable as long as they have a sufficient elasticity for bending back and forth (flexion and extension) and has no effect on the reaction of interest.

Shallow grooves 9 provided on the surface of the base plate 1 are for enhancing the mixture of reactants. The grooves 8 are not restricted in their form to those illustrated in the figure, but can take any forms as long as they allow the ready introduction and effective mixing of samples, or they can be dispensed with depending on the object to be tested.

Spacers 10 are interposed between the thin base plate 1 and the plate strips 7, and these members are closely stuck together to form mixing chambers 3. The spacer 10 is dpen in its top so that samples can be introduced through this opening into the mixing chamber 3. The material of the spacer 10 may have the same elasticity or flexibility as the plate strip 7, or may not have such mechanical properties.

The spacer may be made of an absorbent material, not to mention a synthetic resin and a metal.

In the example illustrated in the figure, the two plate strips 7 are stuck to the thin base plate 1 so that the two mixing chambers are formed on the base plate 1. One plate strip 7 may be adhered at a plurality of spots to the thin base plate 1 thereby forming a plurality of chambers 3; this maneuver allows the formation of a plurality of chambers with one plate strip. At least either the thin base plate 1 or the plate strip 7 should be transparent so that the interior of the chamber 3 can be seen from outside.

Because the thin base plate 1 is larger than the plate strip 7, the opening formed on the thin base plate 1 and leading to the mixing chamber 3 works as an inlet for samples. A sample is placed at the opening and introduced into the mixing chamber 3 through capillary action. A reagent 8 may be placed in the mixing chamber prior to mixture when necessary, as in Example 1. Or, when a reagent 8 is to be placed in the mixing chamber 3, it may be kept at one part of the spacer 10, or soaked in the spacer 10.

A cover film 11 can stick and lift in a reversible manner, and has been firmly fixed by its top end to the thin base plate 1. The cover film 11 can closely cover the thin base plate 1 with the plate strips 7 laid on, and prevents the evaporation of the reagent 8 during its stay in the chamber prior to mixture, and preserves the stability of reaction mixture by preventing its exposure to external air.

Although in the example illustrated in the figure, the thin base plate 1 and the plate strips 7 are firmly stuck each other with the spacers 10 in between, the thin base plate 1 and the plate strips 7 may be stuck together with no spacer intervened.

Further, in order that the entry of samples to the mixing chamber 3 may be facilitated and an effective mixture be achieved, it is advisable that the plate strip should take a curved form as illustrated in Fig. 11. Furthermore, the plate strip 7 and the thin base plate 1 should be shaped in curved forms opposite in their direction prior to use, as shown in Fig. 12. In the figure, the plate strip 7 and the thin base plate 1 are curved so much that the resulting mixing chamber 3 has a measurable opening. However, in practice, it is only necessary for the plate strip 7 and thin base plate 1 to have a disposition towards bending.

Thus, the entry to the mixing chamber 3 need not open prior to use as is shown in the figure. What is required for the plate strip 7 and thin base plate 1 is that they bend opposite ways to provide an opening leading to the mixing chamber 3 when flexed by fingers during use.

OTHER EXAMPLES Figures 5 and 6 represent other examples. They are respectively adaptive for the following tests.

Figure 5 presents a system in which, to four mixing chambers 3 formed on a thin base plate 1, are added a set of chambers 12 as a reference of colorimetry. The spacer 10 forming a part of the mixing chamber 3 is provided, as shown in the figure, with protrusions and depressions along its wall to enhance the mixture of reactants. In these mixing chambers 3, different reagents 8 may be placed prior to mixture as appropriate depending on the objects to be tested.

Fig. 6 represents a system to be used for specifying the type of red cells, where three mixing chambers 3 for recipient blood are placed abreast in the upper row of a thin base plate 1 while three mixing chambers 13 for donor blood are placed in the lower row in a paired fashion. The latter serves as a reference. Anti A, anti B and anti D sera serving as reagents 8 have been placed in order on the bottom or the spacer's base, of the chambers 3 and 13 with the two chambers in the same column as a unit. It has been publicly known that the type of a given blood, that is, whether it belongs to type A, B, O or AB, and to Rh (+) or (-) can be determined by the reaction of the blood to anti A, anti B and anti D sera.

Fig. 7 represents a system in which on the thin base plate 1 are provided three reagent chambers 16 (A, B and C) which are independently connected to a mixing chamber 4.

Further, reagent stoppers 17 are installed between thereagent chambers A and C on the one hand and the mixing chamber on the other, which makes it possible that, when the stoppers 17 are pulled out, reagents in the chambers A and C can enter the mixing chamber.

Moreover, if wet or dry powders, or various germinable substances have been placed in these mixing chambers 3 to be mixed, it will be possible to achieve their separation, germination and storage.

Fig. 8 illustrates an oblong type of system in which the two opposite sides of a plate strip 7 are directly stuck to a base plate 1 by an adhesive 15 with a spacer 10 interposed. When a sample or reagent is allowed to fall dropwise into the sample inlet 4, it flows into a mixing chamber 3 passing along the sides of the spacer 10.

Fig. 9 is another example of oblong type in which the central part of the bottom is made round to allow an effective mixture of reactants and collection of precipitates and sediments. With this system comprising reagent chambers 16 (A, B, C and D), it is possible to mix reagents 8 in the chambers A and B, or those in the chambers C and D before they are transferred to the mixing chamber 3, or to transfer a reagent 8 in the chamber E without prior mixing to the mixing chamber 3.

Fig. 10 represents a system to be used for special tests in which three mixing chambers 3 are provided on a base plate 1, and the chambers are posteriorly covered with a covering member 6 and anteriorly with respective plate strips 7 whose edges have firmly been stuck to the chambers.

Various forms of slit openings for samples to be introduced are prepared on the front surfaces of the plate strips 7.

If the system shown in Fig. 8 is modified in such a way that the plate strip is closed on all sides or on three sides, and an electrophoretic paper or buffer solution instead of the spacer 10 has been placed in the mixing chamber 3, it will be possible to use the system as an instrument for immunological blotting or electrophoresis.

Next, a description will be given below on how mixing is achieved by the present invention with the mixing device presented above.

TESTING PROCEDURE 1 The colorimetric analysis based on the usage of the mixing device shown in Fig. 5 will be given below.

Samples are dropped into the sample inlets 4, and allowed to enter their respective chambers 3 through capillary action. During this procedure, the base plate 1 may be bent to enlarge the space within the mixing chambers 3. In the same manner as above, reagents are introduced into the respective mixing chambers 3.

When samples and reagents are placed in the mixing chambers 3, both ends of the base plate 1 should be held with a hand (for example, one end with a thumb and the other with a middle finger), and the system be bent back and forth so that the base plate 1 is flexed and extended alternately to achieve the mixture of the samples and reagents.

Application of repeated bending to the base plate 1 brings about the deformation of the mixing chambers 3 which is also accompanied with the enlargement and contraction of their inner space, thereby promoting mixing.

When the samples have been mixed thoroughly with the reagents, and exhibit changes in color as a result of reaction, the color of the resulting mixtures in the chambers 3 should be compared with the respective referential colors 12 for determination of the results.

TESTING PROCEDURE 2 The blood typing of a given subject based on the usage of the mixing device shown in Fig. 6 will be presented below.

At first, blood from a recipient is dropped or applied onto the three sample inlets 4 leading to the mixing chambers 3 in the upper row, and allowed to enter the mixing chambers 3 through capillary action. Then, in the same manner as above, blood from a donor is dropped or applied onto three sample inlets 4 leading to the mixing chambers 13 serving as a reference, and allowed to enter the mixing chambers 3 through capillary action.

Or, a set of three oblong pieces of paper or resin arranged in a fan-like manner and serving as a blood collecting device may be prepared, applied to a cut made on the recipient's or donor's ear lobule with a needle to collect drops of blood, and inserted, individually and each with a drop of blood, into the respective mixing chambers 3 or 13.

When the blood samples introduced into the chambers 3 and 13 react completely with corresponding anti sera having been placed in the base plate 1 or on the spacer 10, the reaction products of the mixing chambers 3 in the upper row which represent the results of the recipient and the corresponding results of the donor in the lower row should be compared. If a cover film can be applied to the whole system in such a way that the sample inlets 4 and open slits 14 are closely sealed, it will be readily possible to store the test results in a medical record holder for a certain period of time.

As described above, the testing method for visual inspection of chemical reactions resulting from mixture which the present invention provides consists of: providing a mixing chamber whose interior is visible from outside and which allows a reagent and sample to mix, on a thin base plate with an elasticity; mixing the reagent and sample in the mixing chamber by bending back and forth the base plate after having placed the reagent and sample in the mixing chamber; and determining the nature of the reaction by observing the chamber's interior from outside. With such characteristics, it has an advantage being readily applied for analysis at any place.

Further, according to the mixing device the present invention provides, on the thin elastic base plate is provided a plurality of mixing chambers in which desired reagents can be placed, and to which samples can be introduced from outside, and which are partly or wholly visible from outside, and thus it will be possible to make a rapid and accurate assay using trace amounts of reagents and samples.

Claims (13)

WHAT IS CLAIMED IS

1. A testing method for visual inspection of chemical reactions by mixture which is characterized by: preparing on a thin elastic base plate a mixing chamber for mixing a reagent(s) and sample(s), whose interior is visible from outside; mixing the reagent and sample after having placed them in the mixing chamber, by bending back and forth said elastic thin base plate; and determining the result of the reaction by visually inspecting said chamber's interior from outside.

2. A device for visual inspection of chemical reactions by mixture which is characterized by: preparing on a thin elastic base plate a plurality of chambers to which a sample(s) or reagent(s) can be introduced (injected) from outside, whose individual chambers are independently built or connected each other, and which are partly or wholly visible from outside; and placing desired reagents in the chambers prior to mixture.

3. The device for visual inspection of chemical reactions by mixture as described in Claim 2 wherein the mixing chambers can be sealed hermetically.

4. The device for visual inspection of chemical reactions by mixture as described in Claim 2 wherein colorimetric references or mixing chambers for colorimetric reference are added to the mixing chambers for test on a thin elastic base plate.

5. A device for visual inspection of chemical reactions by mixture which is characterized by: laying a plate strip(s) on a thin elastic base plate; sticking firmly the plate strip to the base plate at a desired spot(s); and making transparent at least either the plate strip or the base plate.

6. The device for visual inspection of chemical reactions by mixture as described in Claim 5 wherein a sample inlet(s) is provided by making at least one spot on the base plate side of the slit formed between the plate strip and base plate, larger than the free edge of the plate strip.

7. The device for visual inspection of chemical reactions by mixture as described in Claim 5 or 6 wherein a cover film is provided which can closely cover from the plate strips' side the whole surface with the base plate and plate strips overlapped.

8. The device for visual inspection of chemical reactions by mixture as described in Claim 5 wherein the plate strip is endowed with a tendency to bend towards a given direction, or the plate strip and base plate are endowed with a tendency to bend towards opposite directions each other.

9. A device for visual injection of a chemical reaction, which device comprises a chamber at least partially defined by a flexible plate, such that flexing of the sheet causes mixing of any fluid located in said chamber, at least a portion of the interior of the chamber being visible from the exterior of the device.

10. A method of testing a chemical reaction by inspection which method comprises placing the reagents for a given chemical reaction in a chamber of a device according to any one of Claims 2 to 9, flexing the plate to mix the reagents and inspecting the reaction in the interior of the chamber.

11. A device for visual inspection of a chemical reaction substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

12. A method of testing a chemical reaction by inspection substantially as hereinbefore described.

13. Any novel feature or combination of features described herein.