Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
  • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
  • G01N33/54366—Apparatus specially adapted for solid-phase testing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B10/00—Other methods or instruments for diagnosis, e.g. instruments for taking a cell sample, for biopsy, for vaccination diagnosis; Sex determination; Ovulation-period determination; Throat striking implements
  • A61B10/0045—Devices for taking samples of body liquids
  • A61B10/0051—Devices for taking samples of body liquids for taking saliva or sputum samples
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B10/00—Other methods or instruments for diagnosis, e.g. instruments for taking a cell sample, for biopsy, for vaccination diagnosis; Sex determination; Ovulation-period determination; Throat striking implements
  • A61B2010/0009—Testing for drug or alcohol abuse

Definitions

• the present invention is directed to an individual testing method and device and more specifically to a method and device for detecting the presence of specific antigens or specific antibodies produced by drugs in a biological fluid such as saliva and using the device to also positively identify the individual tested by reproducing the fingerprint of the person being tested.
• Previously drug testing has been accomplished by testing individual fluid samples such as urine or blood to determine the presence of drugs in the body. Such testing procedures are very common in the athletic world, prisons, courts of law, and in the general workplace and are many times proscribed by contracts between the individual and his/her employer or labor union which represents the individual or group.
• test fluids are obtained from persons other than the person to be tested or that test fluids become mixed, lost, or cannot be specifically identified with that person after the test comes back with positive results.
• Another problem is that the time for testing is generally too long to obtain results which are timely.
• Saliva is a transcellular fluid produced by several paired salivary glands, particularly the parotid, the submaxillary, the sublingual glands and some other small glands.
• the present invention attempts to overcome the problems which are inherit in the prior art through the use of a specifically designed fingerprint pad device which tests for the presence of drugs or other specified agents in the saliva as well as providing a fingerprint of the person giving the test so that positive identification of the fluid donor is irrefutably obtained.
• a specifically designed fingerprint pad device which tests for the presence of drugs or other specified agents in the saliva as well as providing a fingerprint of the person giving the test so that positive identification of the fluid donor is irrefutably obtained.
• the saliva is collected in the buccal cavity by a specially designed device comprising an osmotically active substance enclosed in a pouch consisting of a semipermeable membrane to form a disc of about 35 mm diameter.
• the family of immunoassays works upon the single principle that is the specific recognition of an antigen by an antibody.
• the specific antigen detection and quantification requires an antibody which recognizes the uniqueness of an antigen.
• One unique binding site serves as an identifying marker for that protein.
• detection can be direct where the antigen- specific antibody is purified, labelled and used to bind directly to the antigen or indirect where the antigen- specific antibody is unlabelled and need not be purified.
• indirect detection the binding to the antigen is detected by a secondary reagent such as labelled anti- immunoglobulin antibodies or labelled protein A.
• a variation that uses aspects of both the direct and indirect methods modifies the primary antibody by coupling to it a small chemical group such as biotin or dinitrophenol (DNP) so that the modified primary antibody can then be detected by labelled reagents such as a biotin binding protein or haptene-specific antibodies such as an i-DNP antibodies.
• Antibodies which are immobilized (irreversibly bound) on a membrane are well known in the art and such antibodies are designed to have binding sites which have high affinity for the epitopes of the antigens carried in the saliva and vice versa. Covalent binding of protein to the membrane surface offers a permanent bond which is irreversible, so that once a protein like an antibody is bound, it will not be desorbed during an assay.
• the principle of affinity chromatography requires that a successful separation of a biospecific ligand is available and that it can be chemically immobilized to a chromatographic bed material, the matrix. Numbers of methods well known in the art have been used to couple or immobilize the ligand to a variety of activated resins.
• Examples of immobilization techniques which exhibit variable linkage are those formed by the reaction of the reactive groups on the support with amino, thiol, hydroxyl, and carboxyl groups on the protein ligand.
• the selection of the ligand is influenced by two factors. First, the ligand should exhibit specific and reversible binding affinity for the substance to be purified and secondly it should have chemically modifiable groups which allow it to be attached to the matrix without destroying its binding activity. (Examples of such are Protein G manufactured by Pharmacia, Hydrazide AvidGel Ax manufactured by BioProbe International, and Actigel-ALD manufactured by Sterogene Bioseparation Inc.)
• a definitive antibody for a given antigen When a definitive antibody for a given antigen is available, it is used to identify the antigen in the sample mixture. Once the antibody combines with the antigen, a means is needed to recognize the complex. This has been accomplished in the past by providing a labelled antibody, such as an enzyme, enzyme link immunosorbent (ELISA) -type assay so that the site is incubated with a chromogenic substrate and a color is developed whose intensity is proportional to the enzyme label present.
• ELISA enzyme link immunosorbent
• the invention is directed toward a saliva antigen collection device for testing and identification.
• the device is in the form of a support member with an absorbent section having a permeable membrane test pad mounted thereon which is coded with specific antibodies.
• the membrane bed antibodies capture specific antigens carried by the saliva to determine the presence in the body of specific drugs or substances. It is, of course, apparent that antigens and antibodies can be switched and either immobilized to capture the other.
• Previously such testing has been accomplished by a series of tests which may involve shifting of the fluid being tested to different containers and removal of the fluid from the person being tested to a place distant from the person which allows fluid misplacement and substitution and questions as to the chain of title of the tested fluid.
• Figure 1 is a schematic exploded view of the test kit components of the invention
• Figure 2 is a schematic view of a swab being placed under the tongue of the user
• Figure 3 is a schematic view of the saliva soaked swab being placed on the support member of the invention
• Figure 4 is a schematic view of the saliva soaked swab placed on the support member and solution carrying labelled antibodies being added to the swab;
• Figure 5 is a schematic view of the finger of the test subject engaging the swab so that the finger is covered with a thin film of mixed saliva and solution complex before touching the testing pad;
• Figure 6 is a schematic view of the solution complex covered finger of Figure 5 pressed against the test pad;
• Figure 7 is a top plan view of the finger pad surface shown in Figure 1 having the capacity to test for multiple drugs used with the present invention
• Figure 8 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing a negative test;
• Figure 9 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing bad reagents;
• Figure 10 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing cocaine positive test results;
• Figure 11 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing opiates positive test results;
• Figure 12 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing PCP positive test results;
• Figure 13 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing THC positive test results
• Figure 14 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing methamphetamine positive test results
• Figure 15 is a top plan view of the surface of the pad of Figure 7 after a fingerprint has developed on the surface showing alcohol positive test results.
• a swab 20 is removed from a sterile swab package 22 which is packaged with or attached to support member 30.
• the swab is is placed under the tongue 101 of the test subject 100 to obtain a saliva specimen as is shown in Figure 2.
• the swab after it is soaked with saliva is then placed in an incubation channel 31 and basin 32 cut in support member 30.
• the support member 30 has an absorbent section 34 which includes an absorbent pad 36 upon which is mounted a membrane 38 impregnated with specified antibody or antigen which will capture specific antigen or antibodies produced in the human body by a drug, biological agent or substance which has been taken by the individual.
• the swab 20 and subsequently membrane 38 is then incubated with a chromogenic substrate solution 40 as shown carried in bottle 42 and a color fingerprint 44 is developed whose intensity is proportional to the enzyme present.
• a color fingerprint 44 is developed whose intensity is proportional to the enzyme present.
• the addition of the chromogenic substrate to the saliva soaked swab eliminates the need to add another liquid to develop the color on the membrane surface.
• a reverse fingerprint will be developed by the deposit of colloidal gold particles.
• a secondary antibody is premixed in the solution added to the saliva and complexes with the antigen in the saliva prior to applying the fingertip to the membrane to produce the fingerprint.
• This secondary antibody is provided with microsome labelling which colors the fingerprint in negative or reverse order of a normal print in that the valleys contain a majority of colloidal particles.
• the enzyme in the conjugate serves as an indicator that upon reaction with substrate demonstrates the presence of unknown in the sample.
• the chromogenic substrate provides a detection for the conjugate enzyme and the color produced is proportional to the amount of the unknown in the sample.
• the preferred substrate used in the present invention is that of colloidal gold.
• Gold is biologically inert and has very good charge distribution. It is now becoming widely available in many useful forms. Its detection can be enhanced using several silver deposition methods available commercially. Colloidal gold also can be detected easily in electron microscopy applications and can be prepared in discrete and uniform size ranges, permitting double-labelling experiments. Several commercial companies have introduced silver enhancement kits that do not require using a darkroom, permitting development to be monitored under the microscope or by the naked eye. Colloidal gold particles bind tightly but not covalently to proteins at pH values around the protein's pi. Colloidal gold particles conjugated with a wide range of anti-immunoglobulin antibodies, protein A or streptavidin are available commercially. Because some of the bound protein may slowly dissociate from the gold particles, the colloid can be washed if desired before use to remove free protein.
• Gold labels give higher resolution than enzyme- based methods and avoid the problems of substrate preparation and endogenous enzyme activity. Until recently the gold labels lacked sensitivity at the level of light microscopy, but the recent development of the photochemical silver method of amplification has overcome this problem.
• the gold particles become coated in metallic silver and yield a black-brown label, best visualized by bright-field optics.
• Gold labelling methods are compatible with many histoche ical strains. Gold labelling reactions are very readily controlled, as the appearance of staining can be monitored directly and continuously under the microscope or with the naked eye.
• the membrane 38 which is preferably of latex has a surface 50 which as shown in Figure 7 is divided up into separate segment test areas which are provided immobilized ligands such as antibodies or antigens which attach to predetermined labelled ligands carrying specific substances.
• the test segment areas are shown reacting or holding cocaine molecules 51, opiates 52, PCP 53, THC 54, methamphetamine 55 and alcohol 56 although other substances can be substituted. Presence of one or more of the aforenoted drugs or predetermined substance in the saliva provides the corresponding segment with a negative no color or inhibition assay.
• a control center 57 and outer ring 58 are provided to provide backup accuracy.
• the central control area is porous to prevent fluid entrapment on the surface of the membrane.
• a chromogenic substrate provides a sensitive detection method for the enzyme.
• the following tables I and II set forth chromogenic substrates yielding water- insoluble products and water-soluble products that can be used in the invention in place of the colloidal gold substrate previously noted. TABLE I Chroao enic Substrates Yieldin Water-Insoluble Products
• the color produced is proportional to the amount of unknown in the sample, providing the unknown is the limiting component of the system.
• the BCIP,NBT Phosphates Substrate System generates a dark purple stain on membrane sites bearing phosphatose.
• Alkaline phosphatase catalyze the dephosphorylation of 5-bromo-4- chloro-3 indolyl phosphate which initiates a reaction cascade resulting in intense color formation.
• Binding of an antibody can be detected by a variety of reagent systems as is the case for antigen bound to the antibodies of the membrane.
• I- labelled antimouse immunoglobulin or I-labelled protein A may be used.
• Antimouse immunoglobulin conjugated directly to alkaline phosphatase or to peroxidase may be used, together with appropriate chromogenic substrates.
• the biotin-avidin peroxidase system together with appropriate chromogenic substrates.
• the biotin-avidin peroxidase system (for example, the Vecta ⁇ tain ABC system supplied by Vector Laboratories) is particularly sensitive.
• the solid phase membranes eliminate handling, allow the product configuration to be cut in the desired shape or format for placement on a base, and provides faster kinetics and increased protein binding.
• Protein binding to solid plastic substrates has been found to be a non-stoichiometric process and varies greatly by the type of plastic used. Binding is not specific and generally occurs through electrostatic and hydrophobic interreactions between plastic and proteins.
• Membrane substrates overcome many of the problems inherent in solid phase immunoassays as they combine the qualities of a solid substrate with a range of expanded capabilities and, due to their porosity and consequential large surface area, have a high protein binding capacity. A protein binding capacity is increased by using smaller pore sized membranes whose total binding surface increases for an equivalent frontal surface.
• Membranes which can be used in the present invention in addition to the noted latex can be constructed of nitrocellulose, nylon, cellulose or IAM produced by Millipore Inc.
• the choice of adsorbing matrix depends on the physical properties such as sensitivity, binding capacity, stability or bound molecules and compatibility with the assay system.
• the preferred membrane used is polystyrene latex because the fingerprint color is retained.
• the reaction tube is prepared with 25 mg of washed latex, 1.0 mg/ml antibody and lOmM Tris Buffer, pH 7.8 Q.S. to 2.0 ml total volume. The reaction tube is incubated for 2 hours at 37°C with rotation.
• the tube is then (a) spun at 2,000-4,000 XG (depending on size of latex) to remove unbound antibody and (b) the beads are resuspended in 3.0 ml of deionized water and the latex is washed three times repeating steps (a) and (b) above and the washed latex is resuspended in 500 ul of PBS (pH 7.4) plus 1.0% BSA plus 4% sucrose and .05% azide, and the sonicate is bathed if necessary to disperse the latex.
• Membranes such as nylon and cellulose, can be modified to create surface sites for covalent binding of proteins.
• Nitrocellulose is one of the most commonly used membranes due to it's high affinity for proteins and cellular macromolecules.
• IAM polyvinylidenedifluoride
• the base polymer of IAM is hydrophobic and binds proteins.
• IAM permits a high degree of control over the extent of protein binding and the user can reproducibly immobilize nanogram to microgram quantities of protein on the surface to suit various assay requirements. Binding the protein to IAM surfaces occurs primarily though the epsilon amino group of lysine, which contrasts the binding proteins to nitrocellulose, nylon or plastic where the bonding is ionic or hydrophobic.
• nitrocellulose which provides an excellent matrix for blotting proteins and nucleic acids.
• the nitrocellulose may be cut into whatever shape is required and has the useful characteristic that the amount of protein in a fingerprint will be clearly visible.
• Pure nitrocellulose adsorbs proteins, nucleic acids and other cellular antigens. These adsorbed substances often retain antigen- antibody binding activity and can be visualized using ultrasensitive, enzyme amplified immunostaining methods so that a chromogenic stain marks the location of the adsorbed materials.
• This approach uses a technique called Dot ELISA, (which also can be utilized with the Nylon, IAM, plastic membranes) whereby nanogram amounts of protein are directly applied to nitrocellulose.
• Dot ELISA One important advantage of Dot ELISA is the ability to perform multiple enzyme immunoassays in a single test procedure using as little as one microliter of antigen or capture antibody solution. Nanogram amounts of capture antibodies dotted onto a single membrane can be used to screen simultaneously for a variety of antigens.
• the reactant is diluted in coating ' solution and dotted onto the damp membrane. While the optimal concentration will vary from reactant to reactant, for complex antigens 0.1 - 1.0 mg/ml is suitable. Following membrane blotting excess binding sites are blocked by thoroughly soaking both sides of the membrane in Diluent/Blocking Solution. Any of a variety of reservoirs can be used.
• the Diluent/Blocking Solution contains 1% bovine serum albumin (BSA) in phosphate buffered saline which protects adsorbed protein from surface denaturation.
• BSA bovine serum albumin
• membranes can be stored dry at refrigeration temperatures for several months without loss of activity.
• the adsorption of an antigen or capture antibody onto the nitrocellulose membrane can be accomplished by Antigen Detection ELISA, which is the simplest method for detection of antigen.
• Indirect Antibody ELISA which is capable of detecting either antibody or antigen, depending on which is defined as the unknown or Antibody Sandwich ELISA which is accomplished by adsorption of an antigen or capture antibody, washing each reagent of any free or unattached reactant and adding another reagent to build step by step a molecular sandwich on the membrane surface which is completed by the addition of an enzyme-antibody conjugate.
• TM ELISAmate
• a swab 20 is removed from its sterile pack 22 which may be attached to or included with the test kit.
• the swab 20 is placed under the tongue 101 of the test subject 100 for one minute.
• the swab 20 is placed in the incubation channel 31 and basin 32 which forms the swab holder of the support member 30.
• Three drops of solution 40 provided with a microsome gold label or silver treated gold label are added to the saliva swab and one minute is allowed for absorption and mixing.
• the index finger 110 or thumb of the test subject is pressed against the swab in its swab holder as shown in Figure 5 for 10 seconds and the finger or thumb is lifted off the swab and immediately pressed and held on the test pad 36 for 30 seconds. The finger or thumb is lifted off the test pad and after two minutes the result is read on membrane surface 50.

Landscapes

• Health & Medical Sciences (AREA)
• Immunology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Biomedical Technology (AREA)
• Chemical & Material Sciences (AREA)
• Hematology (AREA)
• Urology & Nephrology (AREA)
• Biotechnology (AREA)
• Microbiology (AREA)
• Cell Biology (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Pathology (AREA)
• Investigating Or Analysing Biological Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=24681079

Family Applications (1)

Country Status (4)

Families Citing this family (17)

Citations (1)

Family Cites Families (1)

• 1992
  • 1992-03-12 CA CA 2062900 patent/CA2062900A1/en not_active Abandoned
  • 1992-03-12 WO PCT/US1992/001793 patent/WO1992016842A1/en not_active Application Discontinuation
  • 1992-03-12 EP EP92908425A patent/EP0637383A1/de not_active Withdrawn
  • 1992-03-12 AU AU15890/92A patent/AU1589092A/en not_active Abandoned

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events