The present invention relates to devices and methods for diagnostic analysis. More particularly, the invention relates to a device, method, and a kit for processing a sample contained in a swab.
Diagnosis of biological samples has gained increased importance in medical treatment and practice. Rapid identification of disease-causing organisms in biological samples is very important. Several diagnostic tests exist for detecting analytes in biological samples, within a period of minutes, as opposed to the traditional period of days involved with bacterial cultures. For example, there are devices for testing Group A Streptococcus (Strep A) within minutes, which allow quick diagnosis and treatment.
In many instances, to carry out a diagnostic test such as Strep A, the operator inserts a swab containing a sample into a flexible test tube and then manually squeezes the tube to remove the sample from the swab. After the swab is removed from the test tube, the tube is capped with a dropper cap. The capped tube is inverted and the sample is then applied to the diagnostic test device. This approach thus involves the use of manual steps that are prone to user error, and the assembly of discrete components, which, if performed incorrectly, may result in spillage, contamination, and/or the possibility of the user being exposed to biohazardous materials.
Another approach is disclosed in U.S. Pat. No. 5,415,994, entitled “Lateral Flow Medical Diagnostic Assay Device with Sample Extraction means”; Imrich et al, issued May 16, 1995, which is fully incorporated herein by reference. The Imrich patent discloses a device, method, and kit for detection of analytes in samples. This device includes an open extraction chamber, into which a user places a sample-containing swab. The user then pours an extraction fluid over the swab. Extracted sample is removed from the extraction chamber through an exit port, and is then passed to a sample receiving zone and subsequently tested. Thus, the sample is initially extracted in an open container, and then removed from this primary container prior to application to a test device.
This approach too, however, has drawbacks. For example, sample extraction involves user-implemented steps that are subject to error, presenting opportunities for inaccuracies, contamination, and/or exposure to biohazardous materials. In this regard, incomplete coverage of the swab with extraction fluid may adversely affect sample extraction, while the open nature of the extraction container during the extraction steps presents opportunities for sample contamination by foreign objects and/or spillage to potentially expose the user to biohazardous materials. Moreover, there has recently been concern that a Clinical Laboratory Improvement Amendments (CLIA) waiver would not be available for a diagnostic test if the extracted sample were removed from the primary (extraction) container prior to delivery of the sample to the test device, ostensibly due to the aforementioned contamination and exposure concerns.
Thus, a need exists for a single device that allows both the extraction of the sample from the swab, and delivery to a diagnostic test device, in a single, closed container, while reducing the risk of user error, sample contamination, and/or exposure to biohazardous material.
According to an embodiment of the invention, a device for processing a sample contained in a swab for diagnostic analysis comprises a chamber comprising a first chamber portion and a second chamber portion for receiving the swab and a processing fluid, wherein at least one of the first and second chamber portions is flexible; a divider is positioned in the chamber and is able to transfer the sample to the second chamber portion, and there is a delivery channel in fluid communication with at least one of the first and second chamber portions, to deliver a processed sample for diagnostic analysis.
Another embodiment includes a method of processing a sample contained in a swab for diagnostic analysis, the method including introducing the swab into a first chamber portion of a chamber, and passing the swab through a divider in the chamber to transfer the sample into a second chamber portion of the chamber, so that the second chamber portion contains a processing fluid. The method also includes displacing a processed sample through a delivery channel in fluid communication with at least one of the first and second chamber portions for diagnostic analysis.
Another embodiment includes a diagnostic kit for analyzing a sample, the diagnostic kit comprising a device as described above, at least one processing fluid, and a diagnostic test for analysis.
Still another embodiment includes a method of fabricating a device for processing a sample contained in a swab for diagnostic analysis, the method including providing a chamber having a first chamber portion and a second chamber portion for receiving the swab and a processing fluid, in which at least one of the first and second chamber portions is flexible. The method also includes placing a divider in the chamber to transfer the sample for processing, and providing a delivery channel in fluid communication with at least one of the first chamber portion and the second chamber portion to deliver a processed sample for diagnostic analysis.
The present invention relates to a device, method, and kit for processing a sample contained in a swab for diagnostic analysis.
According to an aspect of the invention, as shown in
Generally, the sample will be biological material obtained or derived from a patient or non-patient sample. Biological samples derived from patients can include physiological material such as urine, serum, cerebrospinal fluid, nasal secretions, gastric secretions, sputum, pharyngeal exudates, urethral or vaginal secretions, and the like. Non-patient samples can include microbial contamination of immortalized cell lines, food stuffs, agricultural products, and the like. In some cases, samples may also include non-biological samples. The processing solution (e.g., extraction or lysing fluid) generally is a solution including reagents which will treat the sample to enhance the detection of an analyte or antigen in the sample. Suitable processing solutions may include acids, detergents or chelators. In particular examples, for the immunological detection of Group A streptococcus by devices of the present invention, a swab containing a sample of pharyngeal exudate may be pretreated with an acidic processing solution, such as nitrous acid, to expose Group A streptococcus-specific antigens. Alternatively, to detect Legionella pneumophila by immunochemical means, a swab containing a sputum sample may be pretreated with a processing solution containing a Triton X-100 detergent and EDTA in phosphate-buffered saline.
Optionally, various embodiments may include a cap 140 coupled (e.g., with an integral hinge 142) to the first chamber portion 110 of the device and able to seal the opening 150 of the device in a fluid-tight (e.g., liquid- and air-tight) manner. According to another aspect of the invention, the first chamber portion 110 is relatively more rigid than the second chamber portion 115. According to another embodiment, the second chamber portion 115 is made of flexible plastic, such that the user can squeeze the second chamber portion 115 (e.g., as shown in
As shown in
Use of the divider to remove the sample from the swab eliminates the need for a user to manually squeeze the sample out of the swab, to effectively remove user variability and the associated potential for user error from this sample processing operation. Also, after processing, the sample is ready for delivery, via the delivery channel, to a testing device for diagnostic analysis. Thus, the user is not required to move the sample to an intermediate chamber prior to testing.
Embodiments of the present invention thus eliminate steps prone to user error, and provide a single, closeable container for both sample processing/extraction and delivery to a test device, while optionally capturing the swab therein, for substantially reduced potential for inaccuracies, contamination, and/or exposure to biohazardous materials. The relatively simple, unitary nature of these embodiments may also facilitate low cost manufacture, use, and disposal of the device.
According to another embodiment, as shown in
In a particular embodiment, the displacing 415 further includes squeezing the second chamber portion 115 to displace the processed sample. The second chamber portion 115 can be made of flexible plastic to allow a user to squeeze the second chamber portion 115 to displace the processed sample. The method may further include withdrawing the swab from the second chamber portion 115 after processing the sample. Once the sample is extracted with the processing fluid, the swab can be removed or the swab can be broken off and retained within the first chamber portion 110. In this regard, the swab may be captured in the first chamber portion 110, such as by using the cap 140 to close the first chamber portion 110, to manage biohazardous waste and reduce the risk of contamination.
According to embodiments of the present invention, a decrease in the internal volume of the device enables the delivery of the sample for diagnostic analysis, as illustrated in
According to an embodiment, a diagnostic kit for analyzing a sample comprises a device 100, as described earlier and at least one processing fluid. The processing fluid includes reagents which will treat the sample to enhance the detection of an analyte or antigen in the sample. In particular embodiments, the sample may contain, for example, an antigen selected from the group consisting of Group A Streptococcus antigen, Group B Streptococcus antigen, Group C Streptococcus antigen, Pseudomonas aeruginosa antigen, Chlamydia trachomatis antigen, Neisseria gonorrhea antigen, Legionella pneumophila antigen, and herpes simplex virus antigen. The kit may further include a diagnostic test such as a diagnostic cassette 500 shown in
In another embodiment, the invention includes a method of fabricating a device for processing a sample contained in a swab for diagnostic analysis, including providing a chamber comprising a first chamber portion and a second chamber portion for receiving the swab and a processing fluid, in which at least one of the chamber portions is flexible. The method also includes placing a divider in the chamber to transfer the sample for processing, and providing a delivery channel in fluid communication with at least one of the first chamber portion, and the second chamber portion to deliver a processed sample for diagnostic analysis. According to another embodiment, the method further includes coupling a cap to the first chamber portion to seal the device.
It should be understood that any of the features described with respect to one of the embodiments described herein may be similarly applied to any of the other embodiments described herein without departing from the scope of the present invention.
The foregoing description is intended primarily for purposes of illustration. Although the invention has been shown and described with respect to an exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US08/86049 | 12/9/2008 | WO | 00 | 6/10/2010 |
Number | Date | Country | |
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61012868 | Dec 2007 | US |