Containers For Laboratory Use

Abstract

A container having an upper open end through which the container can be filled with liquid, such as a specimen of blood, and a closure fluid-tightly closing the open end of the container. The closure has a portion within the opening which is pierceable by a sedimentation tube or the like and the portion of the closure within the opening is constructed to close fluid-tightly about the outer surface of the tube when the latter is pushed through the closure.

Description

This invention relates to a container for laboratory use, particularly but not exclusively for use in collecting blood for sedimentation tests, i.e. determining the rate of sinking of blood corpuscles.

For various purposes in medicine, including veterinary medicine, a large number of experiments are carried out with blood, urine and other liquids, and it is important for the sake of efficiency that the many small specimens of liquid be easily protected and transported and subsequently be readily available for use.

When it is required to measure the rate of sinking of blood corpuscles, transfer of a mixture of blood and citrate solution from a specimen in a glass container to a sedimentation tube is effected by dipping the sedimentation tube into the specimen and then by mouth sucking the mixture into the sedimentation tube to a height of a little more than 200 mms. The sedimentation tube is then closed with a finger and by means of the finger the height of the mixture is adjusted to 200 mm. after which the sedimentation tube is placed in a frame. This well-known method is difficult to operate, is repulsive to some persons and involves the danger that one may easily suck the mixture into one's mouth and therefore expose oneself to disease, e.g. infectious jaundice.

Numerous attempts have been made to avoid the sucking of the mixture into the sedimentation tubes without a method being found which, in practice, does not result in increased expenses. For example, the sedimentation tube has been provided with a nonreturn valve, which is not only expensive but also makes it difficult to fill the sedimentation tube to the correct height and in particular to clean the sedimentation tube after use. Internally ground cylinders have also been proposed which have a diameter such that the sedimentation tube upon being inserted into the cylinder, acts as a piston so that the mixture is pressed upwardly into the tube. Such cylinders are expensive and therefore cannot be thrown away after use but must be cleaned. Also, without additional measures, they are not suited for transporting a specimen.

The present invention provides a container for laboratory use, having a closure which has a thick peripheral part adapted to tighten against an edge of the container and having a thinner middle part adapted to tighten around a sedimentation tube or pipette upon being pierced by such tube or pipette.

This arrangement ensures that the liquid, which is tightly enclosed in the container and which can therefore be readily transported, can be removed in the desired amounts from the container by insertion of a sedimentation tube or a pipette into the container, the liquid being forced into the sedimentation tube or the pipette following the insertion thereof. Moreover, it ensures that the laboratory technician does not get into contact with the liquid. The container, together with the remaining liquid, may be thrown away after use.

The container is particularly suited for collecting blood for measurement of the rate of sinking of the blood corpuscles, in which case the container, together with the inserted sedimentation tube can be placed in a frame until the sedimentation test has been completed, after which both can be thrown away. Instead of this, the sedimentation tube can be drawn from the container, whereby the surface of the sedimentation tube is cleaned of the fluid mixture by its passage through the closure, while the container with its blood and citrate may be thrown away.

According to the invention the diameter of the thinner middle part of the closure may correspond to the outer diameter of a sedimentation tube, so that the thinner middle part by insertion of a sedimentation tube into the container is pressed apart and the sedimentation tube bears against the inner side of the peripheral part of the closure to ensure good sealing.

To facilitate the insertion of the sedimentation tube, the middle part of the closure may have a rupturing mark.

The middle part of the container may have a wall thickness which is so small that this part is resilient and can be pressed together, so that liquid can be readily pressed up from the container into, for example, a pipette. If a sedimentation tube is to be filled with blood from the container the required height of liquid in the sedimentation tube can be adjusted by squeezing the middle part of the container.

The invention is illustrated in the drawing, which shows a vertical, longitudinal section through one embodiment of the container.

A container 1 is made of a suitable plastics material and is provided with an opening defined by annular wall and with a closure 2 which closes the opening of the container in an airtight manner since the closure 2 has a thick peripheral part adapted to close tightly around the outer surface of the annular wall of the container. The closure 2 also has a thin middle part 5 which can be pierced by a sedimentation tube or a pipette. The closure has a substantial inner frustoconical part 6, located within the opening spaced from the inner surface of the annular wall and which is closed at the bottom by the middle part 5 and against the inner side of which the sedimentation tube can bear so that good sealing is obtained by insertion of the sedimentation tube. The upper part 4 of the container has a wall thickness which is sufficiently large to ensure that when the closure is fitted good sealing can be obtained, the upper part of the container having a corresponding stiffness. The middle part of the container has a wall thickness which is so small that this part can be easily pressed together, whereby for example liquid can be pressed upward to exactly the required height in a sedimentation tube. The position at which the large and small wall thicknesses meet each other can indicate the height which the mixture of blood and citrate solution should reach in the container. The lower part or bottom 3 of the container has such a shape that it fits closely around the tip or lower part of the sedimentation tube. In this way sufficient sealing is obtained to ensure that when the sedimentation tube is pushed right into the container the mixture of blood and citrate solution remains at the same height in the sedimentation tube until the rate of sinking of the blood corpuscles is measured.

Claims

What we claim is:

1. A device for laboratory use comprising a container having an opening defined by an annular wall having an outer surface; and closure means for tightly closing said opening, said closure means having an outer peripheral part tightly engaging said outer surface of said annular wall and wall means within said opening integral with said outer part, and a thin pierceable bottom portion integral with said wall means so as to close said opening, said bottom portion having a wall thickness smaller than that of said outer part, and said wall means being constructed to close fluid-tightly about a sedimentation tube when said bottom portion is pierced by said tube.

2. A device as defined in claim 1, wherein said wall means comprise an inner frustoconical part which is closed at the bottom by said pierceable bottom portion, said frustoconical part having an outer surface radially inwardly spaced from the inner surface of said annular wall.

3. A device as defined in claim 2, wherein said pierceable bottom portion and the sedimentation tube to be inserted into said container have substantially equal outer diameters.

4. A device as defined in claim 1, wherein said container has spaced from said annular wall defining said opening a flexible wall portion.

5. A device as defined in claim 4, wherein said container is substantially cylindrical, and wherein said flexible wall portion is an annular wall portion.

6. A device as defined in claim 5, wherein said container has a closed bottom end portion having an inner cylindrical surface of a diameter to tightly engage about a sedimentation tube extending downwardly in said container in engagement with said bottom end portion of the latter.