Chemistry: analytical and immunological testing – Involving diffusion or migration of antigen or antibody
Utility Patent
1991-05-29
2001-01-02
Chin, Christopher L. (Department: 1802)
Chemistry: analytical and immunological testing
Involving diffusion or migration of antigen or antibody
C422S051000, C422S051000, C435S006120, C435S007100, C435S007920, C435S007930, C435S007940, C435S007950, C435S287100, C435S287200, C435S805000, C435S810000, C435S970000, C436S518000, C436S810000
Utility Patent
active
06168956
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to chromatographic assay devices. In particular, this invention relates to chromatographic assay devices which are used to qualitatively or quantitatively test for the presence of clinically important biological molecules.
BACKGROUND OF THE INVENTION
Chromatographic assay systems are well-known and frequently used analytical systems. These assay systems have a wide range of utilities. Recently, they have taken on an ever larger role in providing physicians with information to guide the diagnosis and treatment of a variety of disorders.
Among the most important of such systems are the “thin layer” systems in which a solvent moves across a thin, flat, absorbent medium.
The use of immunoassays as a means of testing for the presence and amount of clinically important molecules has been known for some time. As long ago as 1956, J. M. Singer reported the use of an immune based latex agglutination test for detecting a factor associated with rheumatoid arthritis (Singer, J. M., Plotz, C. M.,
Am. J. Med.
Vol. 22, pp 888-82). These techniques are used in a particularly popular form of chromatographic assays, known as immunochromatography. In their simplest forms, these tests use a disclosing reagent or particle which has been linked to an antibody to the molecule of interest. This combination is then mixed with the specimen and, if the molecule of interest is present, the disclosing reagent-linked antigens agglutinate with the molecule of interest, thereby giving an indication that the molecule of interest is present. The disclosing reagent or particle may be identifiable on the basis of color, magnetic properties, radioactivity or any number of other physical or chemical properties. The specific reactions which are employed vary with the nature of the molecule of interest and the sample which is to be tested.
Immunochromatographic assays fall into two principal categories: “sandwich” and “competitive”. Generally, “sandwich-type” immunochromatographic procedures call for mixing a sample containing a molecule of interest with antibodies to that molecule, which causes an antigen-antibody complex to be formed. The antibodies which are used in this procedure are typically linked to a disclosing molecule or reagent, such as dyed latex, colloidal gold or a radioisotope. This mixture is then applied to a chromatographic medium which contains a band or zone to which antibodies to the molecule of interest have also applied. This medium often takes the form of a device or strips which resembles a “dipstick.” When the complex of the molecule of interest and the antibodies with disclosing reagents or particles reaches the zone of the chromatographic medium with the antibodies, binding occurs and the bound disclosing particles or reagents are localized at the zone or band on the chromatographic medium. This indicates the presence of the molecule of interest in the sample. Quantitative results can sometimes be obtained in this manner.
In addition to immunochromatographic assays, it is also known to use enzyme-based chromatographic assays. These techniques are roughly analogous to immune-reaction based systems, but use an enzymatically catalyzed reaction instead of an antigen-antibody reaction. Other analogous chromatographic assays are also known.
The chromatographic techniques which are available to the clinician are not without their drawbacks. Sometimes the specimen which is to be tested contains cells or particulate matter which can add colors to the chromatographic medium thereby making it difficult to read the test. In some cases, such as tests using fecal samples, particulate matter within the sample can clog the pores of the chromatographic medium making immunochromatography very difficult, if not completely impossible. It is also important (and sometimes quite difficult) to apply the sample to the chromatographic medium so that the sample front will be applied to and move through the chromatographic medium and reach the area where binding is to occur in a uniform, straight-line manner.
Other problems associated with chromatographic devices and techniques which are available to the physician are those of sample preparation and waste generation. It is rarely possible to apply a sample (such as feces) or a sampling device (such as throat swab) directly to the chromatographic media. Several extraction and pretreatment reactions are usually required before the sample can be applied to the chromatographic medium. Conventionally, these preparatory steps are carried out by the physician or a technician in several small vessels, each of which (along with a transfer device, such as a pipette) is thereby contaminated with biological, chemical or radiological wastes, all of which can come into contact with the physician, technician and many others.
Another limitation on the chromatographic devices which are available to the clinician is their inability to perform 2 directional or 2 dimensional chromatography. These chromatographic techniques have long been known to be powerful analytical tools but their complexity relative to simple unidirectional chromatography has made it difficult to apply them in the physician's office.
SUMMARY OF THE INVENTION
In a chromatographic device according to the present invention there are two principal parts, a first and a second opposable component. The first opposable component contains a sample preparation means and the second opposable component contains a suitable chromatographic medium. In operation, a sample is placed on the sample preparation means (along with suitable reagents and solvents) and the sample is thereby prepared for application to the chromatographic mechanism, but is not applied to the chromatographic medium until after the preparatory reactions have taken place. The two opposable components are then brought into opposition, thereby bringing the sample preparation means on the first component into contact with the chromatographic medium on the second component. This applies the treated sample to the chromatographic medium and the chromatographic process then begins. The result can be observed via an appropriate opening or transparent portion of the device.
In another embodiment of the invention, the first opposable component has a sample preparation means and a chromatographic medium which is not in communication with the sample preparation means. The second opposable component contains a communicating means which, when the two components are brought into opposition, establishes a communication between the sample preparation means and the chromatographic medium. In use, the sample is applied to the sample preparation means and the required preparatory reactions are conducted. Once this is accomplished, the two components are brought into opposition and the chromatography is begun.
By locking the two opposed components of the device together, one can permanently encase the sample as well as all materials which have been exposed to the sample or to the chemical, biological or radiological materials used in the assay.
The two opposable components can be constructed of any material which provides suitable mechanical support or the desired degree of protection from the materials which are used in the test. The sample preparation means and the chromatographic medium will necessarily be adapted to the requirements of the particular assay which is to be performed. In an advantageous embodiment, the sample preparation means is an absorbent pad which can retain a suitable quantity of fluid and which has a pore size which allows the absorbent pad to filter out particulate matter which should not be applied to the chromatographic medium.
This unique construction provides a simple, self-contained device which permits the reliable execution of chromatographic assays by persons having only basic laboratory skills and without the risk or expense associated with the generation or leakage of biological, chemical or radiological wastes. This device also facilitates the sequential execution of pretreatment and chrom
Beckman Coulter Inc.
Chin Christopher L.
Harder P. R.
May William H.
Merchant & Gould
LandOfFree
Multiple component chromatographic assay device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiple component chromatographic assay device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiple component chromatographic assay device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2491533