Chemical apparatus and process disinfecting – deodorizing – preser – Analyzer – structured indicator – or manipulative laboratory... – Sample mechanical transport means in or for automated...
Utility Patent
1997-11-19
2001-01-02
Alexander, Lyle A. (Department: 1743)
Chemical apparatus and process disinfecting, deodorizing, preser
Analyzer, structured indicator, or manipulative laboratory...
Sample mechanical transport means in or for automated...
C422S051000, C422S105000, C422S105000
Utility Patent
active
06168758
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to liquid assay devices, and in particular, to liquid sample containers which include a self contained means of assaying such liquid.
DESCRIPTION OF THE PRIOR ART
There is presently a great demand for safe, reliable and easy to use liquid assaying devices. Such devices have uses in a variety of areas such as diagnostic testing of biological fluids, testing of water samples, etc. An example of one such application of the device is in diagnostic and drug testing purposes of urine samples at the screening stage. Screening apparatuses are used by health practitioners as a diagnostic aid. A preliminary assay will help the practitioner to determine the presence of various antigens in a patient's bodily liquids which could, potentially be causing an illness. There is even a greater demand for such diagnostic screening apparatuses due to a widespread fear which has been aroused in the general population by the growing number of people being infected with HIV. Due to the long incubation period of this disease many people have chosen to be screened so that early treatment can be obtained and the spread of this deadly disease can be reduced.
In society at large, there is also a growing concern about drug abuse. It is the policy of many employers to screen employees for the use of illegal drugs. Similarly, athletes are now routinely screened for the presence of banned substances both before and after competitions. To address the need to quickly screen people for these illegal substances, various screening devices have been produced which require manual transfer of a sample liquid from a collecting vessel to an assaying device. A positive test at the screening stage would require the sample to be sealed and then forwarded to a laboratory for more rigorous and complete testing to verify the results of the screening test.
One such device for specifically testing for the presence of non-protein antigens such as most drugs of abuse, is taught by U.S. Pat. No. 5,238,652. This device utilizes a thin layer chromatography membrane for testing for the presence of certain illegal drugs. The assaying device taught makes use of colored latex spheres combined with a specific antibody for binding to a specific antigen (i.e. drug). The latex spheres are applied to a chromatography membrane upstream of an immobilized drug conjugate probe. The antibody/latex complex is picked up by the test liquid and is used to indicate the presence or absence of a specific antigen drug. A positive test is indicated by the absence of a colored line in the area of the drug conjugate probe on the chromatography membrane due to the fact that the antibody will have bound the antigen rendering it unable to bind the drug conjugate probe. A negative test is indicated by a colored line corresponding to the binding of the latex/antibody complex to the drug conjugate probe.
In use, urine drops are withdrawn manually from a collection vial and added drop-wise to a reception cavity on the device. The urine is then absorbed by a pad and moves along the chromatography membrane by capillary action. This particular device is problematic in that the sample liquid must be manually transferred from the collection device to the assay device, being the chromatography membrane. This is dangerous to those conducting the assay as there is exposure to the sample which could include harmful materials. Also, the test sample is subject to contamination in the transferring process which reduces the reliability of the assay.
U.S. Pat. No. 5,403,551 teaches an assaying apparatus which also uses a chromatography membrane to indicate the presence or absence of specific antigens. As before the use of a latex/antibody complex will display a colored line in the absence of a specific analyte.
This assaying apparatus comprises a collecting vessel and an assaying device as one unit. A sample is introduced into a collecting chamber which is then sealed with a cap. The sample is then introduced into a reservoir through a flow path which is only accessible to the liquid sample when the device is inverted. The reservoir communicates with chromatography test strips and is sized to contain only enough samples to wet the chromatography membranes without flooding them. A mechanical valve is operated by twisting the cap of the device in order to close the flow path of the sample into the reservoir. In this way the sample liquid in the container is sealed off from the ambient air surrounding the container.
This apparatus has a drawback in that it is necessary for a person conducting the assay to remember to twist the cap and thereby close the mechanical valve after inverting the device. A failure to carry out this third step will result in the sample liquid in the container being contaminated by impurities in the ambient air surrounding the apparatus. This apparatus also has a further problem in that it is possible to inadvertently close the mechanical valve prior to inverting the apparatus to start the test. This results in the test not being properly started upon inverting the apparatus. The operator will then waste time waiting for the test to begin before realizing that the valve has been closed. The structure taught by U.S. Pat. No. 5,403,511 suffers from a further drawback in that it is complicated, involving several structural parts. This apparatus is therefore difficult and expensive to manufacture.
As such, there is a need for an assaying apparatus transferred to an assaying device included in the apparatus, without having to remove the sample liquid from the apparatus. A device is needed which has an automatic shut-off valve for preventing contamination of the sample liquid after the assay has been commenced. The automatic properties of such a valve would effectively eliminate the potential for human error in operating such a valve.
There is also a need for a simpler assaying device which is easier and less expensive to manufacture, which accomplishes the function of transferring liquid from a collecting medium to an assaying system without having to manually transfer the sample liquid, thereby exposing the sample liquid to the external environment.
SUMMARY OF THE INVENTION
The present invention is an apparatus, having an assaying device for conducting an assay on a sample liquid. The apparatus has means for collecting a sample liquid and means for transferring a predetermined volume of the collected sample liquid to the assaying device. The apparatus has an automatic valve for sealing the sample liquid in the apparatus from the external environment after the assay has been commenced.
According to one aspect of the invention, an apparatus is provided for conducting an assay on a sample liquid. The apparatus includes a container defining a chamber, the container having an open end for collecting a sample liquid. The apparatus has a removable cap for closing the container. An assaying device is included in the apparatus located on one of the cap and the container for visual observation thereof, the assaying device leaving means for receiving and chemically analyzing the sample liquid and visually displaying the presence of a specific analyte in the sample liquid. The apparatus further includes a defined sub-chamber communicating with the assaying device. The reservoir has a wall which defines at least one opening located to collect a predetermined volume of sample liquid inside the sub-chamber upon submerging the reservoir in the sample liquid in the container. The apparatus also includes a valve member which is located between the reservoir sub-chamber and the assaying device. The valve member is formed of a material that absorbs sample liquid and swells thereby closing off the assaying device from the sub-chamber after a predetermined amount of sample liquid is received by the assaying device.
According to another aspect of the invention, there is provided an apparatus for conducting an assay on a liquid located in a container. The apparatus comprises a cap for closing the container. The apparatus incl
Cox, Jr. Malcolm Francis
Forsberg Bengt Erik
Macartney Charles Terence
Alexander Lyle A.
Merchant & Gould P.C.
Starplex Scientific
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