Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving viable micro-organism
Patent
1995-12-12
1998-01-13
Leary, Louise
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving viable micro-organism
435 4, 435287, 435808, 435291, 435296, 435298, 435299, 422102, 422 8213, 422 681, 215271, 215270, 215274, 215341, C12Q 102, C12Q 100, B65D 3912, B65D 5300
Patent
active
057078238
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to containers and is concerned particularly, but not exclusively, with blood culture bottles.
BACKGROUND TO THE INVENTION
The specification of PCT/GB92/01327 (WO93/03178) concerns a method and apparatus for monitoring the growth of micro-organisms, for example in blood culture bottles. The specification describes and claims, inter alia, a method of monitoring the growth of micro-organisms in liquid culture in a gas-tight container incorporating a flexible diaphragm capable of moving in response to pressure changes within the container, by detecting displacement of the diaphragm, wherein the position or conformation of the diaphragm is repeatedly sensed using distance-measuring means.
Movement of the diaphragm is conveniently detected optically, typically by a laser.
The container is preferably constructed of rigid material, with the sole exception of the diaphram, so that the diaphragm alone is displaced in response to pressure changes within the container. The diaphragm is conveniently made of resilient flexible plastics or rubber material.
The container preferably comprises a culture bottle, having a bottle closure incorporating a resilient flexible plastics or rubber diaphragm (known as a septum) held in place by an annular aluminum overseal that is crimped under a lip extending around the bottle neck.
SUMMARY OF THE INVENTION
It has now been discovered that the diaphragm of such a container is with advantage made of chlor-butyl rubber.
In one aspect the invention thus provides a gas-tight container incorporating a flexible diaphragm, wherein the diaphragm comprises chlor-butyl rubber.
The properties of chlor-butyl rubber are found to be particularly well suited to the requirements of an optical monitoring system, eg as disclosed in PCT/GB92/01327 (WO93/03178).
Chlor-butyl rubber can be relatively light in colour and relatively non-absorbent at laser wavelengths which is an advantage for optical monitoring purposes, enabling greater sensitivity of detection than is possible with diaphragms of dark colour. For example, chlor-butyl rubber can be white, pink, red or blue at least. Blue is found to be a practical colour to use as it is compatible with laser monitoring and also cosmetically attractive (not contrasting too much with any blood left on the surface). Chlor-butyl rubber thus represents a significant improvement compared with alternative diaphragm materials such as butyl rubber, which is dark grey or black and which is relatively absorbent at laser lengths and so presents problems for optical monitoring.
Chlor-butyl rubber also has the necessary property of being substantially impermeable to gas, even over extended periods, so that a gaseous atmosphere can be maintained within the container even during prolonged storage. This is not possible with certain other materials, such as silicone rubber.
Chlor-butyl rubber is also able effectively to seal small punctures, eg. made when introducing a sample to be tested to the container via a needle passed through the diaphragm. A chlor-butyl rubber diaphragm can thus effectively seal needle "tracks" made when introducing samples, eg. blood samples, to the container.
Chlor-butyl rubber is also available in a range of hardness values (eg covering the range 40 to 50 Shore at least) that are well suited to the requirements of a pressure monitoring system, eg as disclosed in PCT/GB92/01327 (WO93/03178). Furthermore, because the hardness can be varied over a range of values it is possible to some extent to modify the sensitivity of the pressure responsiveness of the diaphragm by varying the hardness.
Furthermore, chlor-butyl rubber has the advantage of being mouldable, so that a chlor-butyl rubber diaphragm of any desired shape, configuration and thickness can be readily produced by a moulding process. A thickness in the range 2.7 to 3.2 mm is generally found to be suitable.
The container conveniently comprises a generally conventional culture bottle, typically made of glass. However, the bottle preferably has
REFERENCES:
patent: 3781779 (1973-12-01), Tallman
patent: 4248355 (1981-02-01), Kolb et al.
patent: 4547900 (1985-10-01), Larkin et al.
patent: 4773552 (1988-09-01), Boege et al.
patent: 5051360 (1991-09-01), Waters
Webster's Dictionary, p. 131 and p. 305, 1984 Month Not Available.
Anderson Judith Marjorie
Carr Anthony Hugh
Holbrook Roy
Leary Louise
Oxoid Limited
LandOfFree
Containers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Containers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Containers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-325362