Abstract: Apparatus for performing determinations of immune reactants (e.g., antigens, antibodies) in bodily fluids includes multiple test units having respective elongated rods with transversely-expanded tips at their distal ends. The tips are each coated with respective immune reactants (e.g., allergens) which react in a known manner with respective allergen-specific or allergen-binding antibodies in human serum. The test units are color-coded to identify the allergen coatings and are supported at their proximal ends and positionally identified on a strip. By correlating the color code to a chart, the specific immune reactant (e.g., allergen) coating can be easily identified. The supporting strip for the test unit has through-holes which frictionally engage the proximal ends of the test unit rods with a spacing that permits all of the supported test units to be simultaneously inserted into an assembly of reaction containers arranged in a linear array.

Abstract: The present invention provides methods and kits for determining the presence or amount of a substance by detection of a colloidal dye associated with agglutinated particles. The disclosure of the present invention shows that the use of a suspension of colloidal dye, which contains dye unattached to the particles to be agglutinated, enhances the amount of colloidal dye associated with the particles following agglutination. The methods and kits are disclosed in direct and indirect (e.g., competitive) formats. In one aspect, the present invention provides methods and kits utilizing a single colloidal dye. In another aspect, methods and kits are provided which include two colloidal dyes, wherein one colloidal dye functions as a background-enhancing dye.

Abstract: The invention relates to immunoassay reagents that are both sensitive and specific and which require no sample pretreatment. The invention reagents are particularly useful for assaying digoxin concentrations in patient sera. More particularly, the invention relates to methods and kits comprising (A) an immunoreactant immobilized on a support; and, (B) a buffer agent comprising (i) a buffering agent, (ii) sodium chloride, (iii) choline chloride, (iv) a polysaccharide, (v) fatty-acid-free serum albumin, and (vi) a non-specific reaction suppressor of the formula: ##STR1## wherein X is --NH--(CO)--NH--, --NH--(CS)--NH--, or --N.dbd.C.dbd.N--, R.sub.1 and R.sub.2, which may be the same or different, are C.sub.1 -C.sub.5 linear or branched alkyl groups, or R.sub.1 and R.sub.2, together with nitrogen, is ##STR2## or the metho-p-toluenesulfonate salt thereof, Y, which may be the same or different, is any of H, OH and halogen,R.sub.3 is --NR.sub.1 R.sub.2, --NH.sub.

Abstract: A macromolecular microparticle composition formed by dehydrating an aqueous macromolecule solution and crosslinking the dehydrated macromolecules with a crosslinking agent while in a liquid phase or with heat. Preferably, the dehydrating agent is a polymer mixture of polyvinylpyrrolidone and polyethylene glycol, the crosslinking reagent is glutaraldehyde, and the macromolecule is a protein, most preferably an immunoglobulin. Methods of use for research, diagnostics and therapeutics are also provided.

Abstract: Disclosed are pH dyes containing a suitable compatible substituent which permits binding of the dye to a solid support. Also disclosed are methods for synthesizing such dyes prior to their coupling to the solid supports.

Abstract: A patient's health is diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more groups of particles such as lyposomes or plastic beads of different densities for each group. Each group of density-defined particles carries antigens or antibodies which are specific to a complement antigen or antibody which may be in the blood sample being tested, and which are indicative of the patient's health. A label-tagged antibody which is specific to all bound antibody/antigen couples is added to the blood sample so as to form labelled antibody+antigen-antibody complexes (AAAC) in the blood sample. Upon centrifugation, the complexed particles will settle out in different areas in the tube according to the respective density of the particles, and the degree of label emission of the particle layers can enable qualitative or quantitative analyses of the blood sample to be made.

Abstract: The present invention provides methods for tagging and tracing materials using nucleic acids as taggants. The process of tagging involves altering a substance in a manner that allows for the subsequent identification of the substance by detecting the alteration. The alteration disclosed herein involves nucleic acids.

Abstract: An assay provides for detecting the presence of an analyte in a sample. Sample is applied to move through three zones. A mobilizeable receptor capable of binding to the analyte is present in the first zone. A trap for unbound receptor, consisting of immobilized ligand, is present in the second zone. Receptor bound to analyte will not bind to the ligand; unbound receptor will bind to the ligand. Mobilization and migration of the receptor can be detected in the third zone, which positively indicates that analyte is present. A device for carrying out the method is also provided.

Abstract: The present invention provides a test strip for detecting, in a sample from a human subject, the presence of an antigenic substance which comprises a solid support, an antibody directed against the antigenic substance bound to a first discrete area on the solid support, an anti-human antibody bound to a second discrete area on the solid support as a positive control, and an antibody directed against an antigen which does not naturally occur in human subjects bound to a third discrete area on the solid support as a negative control. The present invention also provides a test strip for detecting, in a sample from a human subject, the presence of an antibody which comprises a solid support, an antigenic substance bound to a first discrete area on the solid support, an anti-human antibody bound to a second discrete area on the solid support as a positive control, and a negative control bound to a third discrete area on the solid support.

Abstract: In an immunoassay for determining the amount of a target substance in a sample using photothermal deflection spectroscopy to determine the amount of bound label, a sandwich procedure is used which comprises reacting the target substance with two antibodies or antigens, one labelled with a compound having photothermal deflection activity, and the other immobilized on a carrier capable of amplifying that photothermal conversion activity of the label.

Abstract: A method is described for the use of monoclonal antibodies in a sensitive immunoassay for halogenated dioxins and dibenzofurans in industrial samples which contain impurities. Appropriate sample preparation and selective enzyme amplification of the immunoassay sensitivity permits detection of dioxin contaminants in industrial or environmental samples at concentrations in the range of a few parts per trillion.

Abstract: The invention provides a method capable of determining the presence or absence of each of a plurality of different ligands in a specimen. The specimen is contacted with a predetermined number of different homogeneous populations of fluorescence beads having one or more predetermined antiligands affixed to their surface. The specimen and bead mixture is analyzed using a means having a single parameter for measuring the fluorescence per ligand to determine the number of nonagglutinated beads, the number of agglutinated beads, the number of bead aggregates, and for each aggregate, the number of beads it comprises. This information is used to correlate the presence or absence in the specimen of each of the different ligands analyzed for. The method of the invention thus provides for the simultaneous determination of a predetermined number of ligands in a specimen using only a single bead contacting step.

Abstract: Useful materials for diagnostic tests, affinity chromatography, enzymatic reactions and immunoassays are prepared by covalently attaching reactive compounds containing reactive amino or sulfhydryl groups to polymeric particles having pendant carboxyl groups on the outer surfaces. Such reactive compounds include biologically reactive species, such as enzymes, polypeptides and proteins. This attachment is carried out using carbamoylonium compounds which react with the carboxyl groups to form intermediate reactive groups which then react with the amino or sulfhydryl groups to form a covalent linkage between particle and reactive compound. A kit comprises polymeric particles having carboxyl groups on the outer surfaces, and a carbamoylonium compound.

Abstract: The present invention is directed to a membrane-based immunoassay method for an analyte of interest having at least two sterically separate antigenic sites. The method comprises providing a reactive membrane having a calibration zone and a test zone, wherein the calibration zone is characterized by having a predetermined amount of the analyte of interest immobilized via a first antibody as a first specific binding pair to a solid phase, the immobilized first binding pair being covalently cross-linked such that any remaining binding sites on said first immobilized antibody are substantially incapable of further specifically binding to any additional analyte, but at least some of said analyte is capable of specifically binding to a preselected amount of a labelled second antibody.

Abstract: Methods and test kits are provided for the quantitative or qualitative determination of selected analytes, e.g., cell subsets in a mixed cell population, using a particulate separation reagent and a particulate detection reagent. The invention enables cell monitoring of AIDS patients in a efficient and reliable manner.

Abstract: Disclosed are a method and device for performing sequential analytical reactions involving a first dry reagent and a second dry reagent comprised of two or more components having different rates of solubilization. The invention enables one to fully solubilize the components of the second reagent before they are brought into contact with each other to thereby avoid interference with the reaction kinetics which result when one or both of the components are not fully dissolved prior to their being brought into contact. The invention is especially useful in conjunction with immunoassay formats involving latex bound antibodies and polymeric agglutinators.

Abstract: A particle agglutination-based, stable kinetic method for simultaneously determining the concentrations of multiple analytes in a single fluid sample with the addition of a single reagent, that entails the use of a novel high resolution sheath flow cell, a novel optical flow particle analyzer (FPA), and unidirectional low angle forward light scattering from multiply-sized or refractive indexed, differently coated particles and their aggregates.

Abstract: A process for assaying at least one analyte uses a tracer which includes multiple detectable substances. A tracer composition includes at least one ligand labeled with a particulate label, the particulate label containing at least one detectable substance. Two or more detectable substances in the assay may be in the same particulate label or in different particulate labels conjugated to different ligands.

Abstract: The invention is an apparatus useful in carrying out an analytical assay. The apparatus has a positive and negative control, as well as a site for determining the presence, amount, or lack of an analyte in a sample.

Abstract: A patient's health is diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more groups of particles such as lyposomes or plastic beads of different densities for each group. Each group of density-defined particles carries antigens or antibodies which are specific to a complement antigen or antibody which may be in the blood sample being tested, and which are indicative of the patient's health. A label-tagged antibody which is specific to all bound antibody/antigen couples is added to the blood sample so as to form labeled antibody+antigen-antibody complexes (AAAC) in the blood sample. Upon centrifugation, the complexed particles will settle out in different areas in the tube according to the respective density of the particles, and the degree of label emission of the particle layers can enable qualitative or quantitative analyses of the blood sample to be made.

Abstract: Biologically active reagents are prepared from particles of copolymers having polyoxyalkylene side chains, each of which side chains has a molecular weight of at least about 88. The reagents are prepared by covalently attaching biologically active substances, for example antibodies, to the particles, directly or indirectly through reactive groups on the particle surface. These reagents are used to advantage in analytical elements and methods for the detection of specific binding ligands (such as immunological species) and immunoassays, and in purification methods as affinity chromatography reagents. Adsorption of undesirable proteins on the particles of the reagents was considerably reduced because of the specific composition of the particles.

Abstract: The invention relates to a process for the preparation of a sol of a metallic or a non-metallic element, such as selenium, tellurium, gold and silver, wherein said process comprises the reduction of a chemical compound, which contains said element in a reducible state, with a borane compound, such as an alkali metal borohydride or an amine borane, as the reducing agent.

Abstract: A microorganism detection system provides initial warning, confirmation of dentity, and recognition of pathogenic factors in microorganisms from environmental samples. The method and apparatus of the invention uses different sized antibody coated microspheres which react with unknown antigens, are sized by electronic volume sizing, and are sorted by size. The sized particles are quantitated in addition to being sized. The microsphere sizes indicate the presence of specific microorganism groups.The samples can be further analyzed using fluorescent microspheres which agglutinate with the sized microspheres. The presence of specific microorganisms is indicated by a change in the fluorescence of the sample.

Abstract: A particle agglutination-based, stable kinetic method for simultaneously determining the concentrations of multiple analytes in a single fluid sample with the addition of a single reagent, that entails the use of a novel high resolution sheath flow cell, a novel optical flow particle analyzer (FPA), and unidirectional low angle forward light scattering from multiply-sized or refractive indexed, differently coated particles and their aggregates. Also disclosed are two embodiments of an instrument specifically designed to carry out the method of the invention.

Abstract: The invention is directed to new drug hapten analogues comprising:(A) an active ester group;(B) a drug hapten nucleus selected from a hydantoin nucleus or a barbiturate nucleus and(C) a linking chain linking the 3-position of the drug hapten nucleus to the active ester group.

Abstract: The present invention relates to immunoassay methods for detecting and measuring the amount of an analyte in a sample by means of generic anti-hapten antibodies. Also disclosed are multi-analyte immunoassay methods. Reagents, devices, and kits using the anti-hapten antibodies are also disclosed. The present invention also relates to dyed erythrocytes, preferably fixed, which are coated with antibodies. Also disclosed is the use of these dyed erythrocytes in agglutination assays to detect and measure the presence of an analyte in a sample. The analyte can be a hapten, an antigen, or an antibody. Also included are agglutination assays, compositions and kits using these dyed and coated erythrocytes.

Abstract: A simultaneous dual analyte assay for determining the fertile period of the human menstrual cycle. The assay utilizes a capture reaction component consisting of P-3-G immobilized on a microporous membrane, a blocking reaction component consisting of anti E.sub.1 -3-G antibody, a labelled reaction component consisting of gold particle labelled anti E.sub.1 -3-G antibody, and an ambifunctional reaction component consisting of a hybrid immunoreactive substance having an anti P-3-G antibody binding site and a plurality of E.sub.1 -3-G determinant binding sites. An aqueous sample containing P-3-G and E.sub.1 -3-G is contacted with the components and the assay is calibrated to provide a positive assay result only when the concentration of P-3-G in the sample is less than a predetermined concentration and the concentration of E.sub.

Abstract: An analytical test device for competition assay for particular non-protein antigens, such as antigens representing drugs of abuse, is disclosed. The analytical test device is a test kit housing having an opening for introduction of a body fluid sample and a flow path for the body fluid sample. A supply of microscopic colored latex particles is adjacent to the opening along the flow path. A chromatographic membrane support is within the test kit housing for exposing the colored latex particles to the body fluid sample. When non-protein antigens are not present in the body fluid specimen, the colored latex particles accumulate at a predetermined site on the chromatographic membrane by complexing of antibodies on the colored latex particles to a drug conjugate probe on the membrane support to leave a visually perceptible colored mark of the same color as the colored latex particles.

Abstract: A laser magnetic immunoassay (LMIA) method which enables detection of less than picograms of target analyte in milliliter of analyte solution. The method involves the steps of: affixing an antibody or antigen on the surface of non-magnetic carrier particles; immunoreacting the affixed antibody or antigen to capture a target analyte contained in a specimen; preparing magnetic labeled microparticles treated so as to bind with the target analyte; reacting the labeled complex to sandwich the target analyte between the magnetic particles and the non-magnetic carrier particles; separating the free species from the bound species by centrifugation; dispersing the precipitated solid to make an analyte solution; applying a spot magnetic field gradient on the analyte solution and irradiating a selected spot with a laser beam; and analyzing the resulting interference patterns to quantitatively determine the quantity of target analyte.

Abstract: A method of high sensitivity immunoassay characterized by inclusion of processes (A), (B), (C) and (D) described below.Process (A): A process of binding of a solid carrier and a complex comprising the specific antibody or antigenic substance to be assayed in the test solution and one or more active components.Process (B): A process of dissociating said complex from the solid carrier.Process (C): A process of binding this complex to another solid carrier.Process (D): A process of assay for the complex on the solid carrier mentioned in the description of process (C) above.Permitting rapid, high sensitive immunoassay irrespective of whether the subject of assay is an antibody or an antigen, the method of the present invention is very useful for quick diagnosis of various diseases.

Abstract: Methods for determining the presence of a first ligand, preferably a hapten, in a sample suspected to contain the first ligand are provided, along with reagent systems and apparatus suitable for performing the methods. The methods depend upon a color visualization indicating the presence or absence of the first ligand in the sample. Preferred methods comprise contacting the sample with a reagent system which comprises: (1) colored particles which bear on their surface a second ligand which may be the same as or different than the first ligand; and (2) an amount of a receptor which is specific for the first ligand and the second ligand, wherein the amount is sufficient to stabilize the particles. The methods further comprise passing the contacted sample and reagent system through a filter, and then analyzing the color of the filtrate. The presence of ligand in the sample is established where the color of the filtrate is substantially different from the color of the ligand-bearing particles.

Abstract: A method for performing a diagnostic immunoassay by a solid phase separation. To a reaction mixture of a test sample and labeled antibody, which forms a complex of any analyte present in the test sample, is added a solid phase material having a compound capable of binding any excess labeled antibody. The solid phase material is chosen to rapidly settle whereby a solid and liquid phase is formed. The liquid phase can then be extracted to measure the amount of analyte-labeled antibody present therein.

Abstract: The invention provides a method capable of determining the presence or absence of each of a plurality of different ligands in a specimen. The specimen is contacted with a predetermined number of different homogenous populations of fluorescent beads having one or more predetermined antiligands affixed to their surface. The specimen and bead mixture is analyzed using a means having a single parameter of measuring fluorescence per ligand to determine the number of non-agglutinated beads, the number of agglutinated beads, the number of bead aggregates, and for each aggregate, the number of beads its comprises. This information is used to correlate the presence or absence in the specimen of each of the different ligands analyzed for. The method of the invention thus provides for the simultaneous determination of a predetermined number of ligands in a specimen using only a single bead contacting step.

Abstract: The invention relates to a process for preparing standards and controls for immunoassays employing monoclonal antibodies. Monoclonal antibodies are used to isolate a restricted portion of an antigen containing an epitope that determines the specificity of the monoclonal antibody-antigen reaction so as to distinguish it from the antigen as a whole, following fragmentation of the complex antigen by procedures including proteolysis. Isolated epitopes are attached covalently or by physical adsorption to particles to immobilize and stabilize the epitope. The particles can be composed of iodipamide ethyl ester, polyvinyl chloride, polystyrene and other inert substances and can be chemically activated to improve epitope binding and stability. Experimental details demonstrate the binding of lipoprotein epitopes to IDE, polyvinyl chloride and polystyrene and the subsequent reaction of monoclonal antibodies to these particle-stabilized epitopes.

Abstract: A method for immunochemical determination of a hapten in a sample is disclosed, in which(A) a high-molecular compound to which the hapten is bound (reagent A),(B) insoluble carrier particles carrying thereon an antibody to the hapten (reagent B), and(C) magnetic substance-containing insoluble carrier particles carrying thereon an antibody to an antigenic determinant in the high-molecular compound and different from the hapten (reagent C),are used. These three reagents are dispersed in the sample, then, a magnetic field is applied to separate from the reaction mixture unreacted reagent (C) and agglutinated particles formed from the reagent (B) and the reagent (C) through the reagent (A). The amount of the reagent (B) remaining dispersed in the reaction mixture is measured, thereby determining the extent of competitive inhibition to the agglutination of the reagent (B) and the reagent (C) through the reagent (A) by the reaction between the hapten in the sample and the reagent (B).

Abstract: An immunoassay procedure for detection of analytes in urine wherein an immunological reaction is conducted in an aqueous phase containing the urine and a filterable immunocomposite containing an inherently colored gold sol particle is formed if the assay is positive. The colored, gold sol particle containing immunocomposite is collected for direct visual observation on a filter element.

Abstract: Biologically active reactive are prepared from particles of copolymers having polyoxyalkylene side chains, each of which side chains has a molecular weight of at least about 88. The reagents are prepared by covalently attaching biologically active substances, for example antibodies, to the particles, directly or indirectly through reactive groups on the particle surface. These reagents are used to advantage in analytical elements and methods for the detection of specific binding ligands (such as immunological species) and immunoassays, and in purification methods as affinity chromatography reagents. Adsorption of undesirable proteins on the particles of the reagents was considerably reduced because of the specific composition of the particles.

Abstract: Immunoassays for measuring thyroid hormones such as thyroxine(T.sub.4) and triiodothyronine(T.sub.3) are carried out by incubating a serum sample with either (a) unlabeled thyroglobulin and a labeled antibody to a thyroid hormone or to thyroxine binding globulin(TBG), or (B) labeled thyrogloublin and an unlabeled antibody to a thyroid hormone. The thyroglobulin may be immobilized on an insoluble carrier and the immobilized thyroglobulin is preferably modified by succinylation with succinic anhydride. Whole thyroglobulin can be used or the thyroglobulin can be fragmented into smaller peptides prior to use provided the peptides contain at least one T.sub.3 or T.sub.4 residue per peptide. Preferably, the antibody is a monocional antibody and labeling is with an acridinium ester.

Abstract: Analytical reaction cassette and method for performing sequential analytical assay procedures to determine the amount of an analyte in a liquid test mixture. The reaction cassette can be in the form of a substantially square container having a substantially horizontal axis of rotation and incorporated with one or more analytical reagents such that they are contacted with a liquid test mixture in a desired ordered sequence to perform a particular assay procedure. Corners provided by the substantially square configuration of the reaction cassette disrupt the flow of liquids disposed in the reaction cassette upon contact therewith to thereby agitate and mix such liquids. A liquid disposed in the reaction cassette is capable of being manipulated and mixed therein by rotating the reaction cassette about the horizontal axis at sufficiently low velocities wherein the transport of such liquid is noncentrifugal and due substantially only to gravitational force.

Abstract: In a method and an apparatus wherein carriers sensitized by an antibody or an antigen are caused to react to a specimen sample and the condensation of the carriers caused by the antigen-antibody reaction is optically detected by the use of flow cytometry, thereby measuring the antigen or antibody in the specimen sample, a plurality of kinds of carriers differing in optical characteristic are sensitized by different kinds of antibodies or antigens, respectively, whereby a plurality of kinds of antigens or antibodies in the specimen sample are measured at a time.

Abstract: Certain phenalenimine fluorescent compounds represented by the structure ##STR1## wherein R' and R" are independently hydrogen, alkyl, cycloalkyl, aryl or a heterocycle, or R' comprises the carbon and heteroatoms which form a fused ring with the compound nucleus, are useful in biomedical and analytical determinations. These compounds can be used for staining cells, as well as for the determination of various analytes found in human or animal biological fluids. Such determinations can be carried out in solution or by using dry analytical elements. The fluorescent compounds can be reacted with quinone nuclei to form reducible compounds which are also useful in analytical methods. In addition, the compounds can be incorporated into what are known as "loadable" latex particles to form detectable labels and biological reagents.

Abstract: A capillary flow device useful in double capture assays, such as double capture immunoassays, and a double capture assay. The capillary flow device comprises a capillary track, a sample receptacle, a particle collecting means and, optionally, a magnet and a particle concentrator. The assay method is useful for determining any analyte of interest for which there is a specific binding partner.

Abstract: A general method of assay for biological molecules using daylight fluorescent particles. The method described is applicable to assays involving immunological reagents, nucleic acids, hormones and neurotransmitters.

Abstract: Phospholipid conjugate compounds derived from cardiac glycosides and sters useful in liposome immunoassays are disclosed as well as their method of preparation.

Abstract: A lyophilized mixture of reactants for an immunoassay includes antibody-gold sol particle conjugates, antibody latex particle conjugates, polyethylene glycol, a polyethylene glycol p-isooctylphenyl ether detergent and a sugar such as dextrin or trehalose. The polyethylene glycol is present to enhance binding of the immunoreactants and the polyethylene glycol p-isooctylphenyl ether detergent is present to prevent non-specific interactions. The sugar prevents agglomeration of the polyethylene glycol and polyethylene glycol p-isooctylphenyl ether in the lyophilized mixture at room temperature and facilitates retention of a homogenous distribution of the ingredients of the mixture to thereby enhance shelf life and redistribution of the mixture in an aqueous test system.

Abstract: This invention is directed to a ligand-receptor assay for determining the presence or amount of at least one target ligand, capable of competing with a ligand analogue conjugate for binding sites available on a ligand receptor, said ligand analogue conjugate comprising at least one ligand analogue coupled to a signal development element capable of emitting a detectable signal, in a fluid sample suspected of containing said target ligand, comprising the steps of:a. contacting said fluid sample with ligand analogue conjugate and ligand receptor to form a reaction mixture, the relative amounts of ligand analogue conjugate and ligand receptor being such that in the absence of target ligand, and subsequent to substantially equilibrium binding, substantially all of the ligand analogue conjugate is bound to ligand receptor;b. detecting the unbound ligand analogue conjugate;c. relating the detectable signal to the presence or amount of target ligand in the fluid sample.

Abstract: A general method of assay for biological molecules using daylight fluorescent particles. The method described is applicable to assays involving immunological reagents, nucleic acids, hormones and neurotransmitters.

Abstract: A method for determining the presence of a specific binding member bound to first particles in a liquid medium is disclosed. The method comprises providing in combination (1) a liquid medium suspected of containing a specific binding member bound to first particles, (2) means for agglutinating the first particles in relation to the presence of the specific binding member, and (3) second particles having the same or a different specific binding member for said means for agglutinating bound thereto, thereby providing for said means to agglutinate the second particles. Agglutination of the first and second particles are separately detectible and distinguishable by spectroscopic measurement. The medium is incubated and agglutination of each of the particles is determined spectroscopically without separating the first and second particles.

Abstract: A method and device of quantitatively assaying an immunologically reactive substance of clinical interest, wherein the method includes the steps of grafting an immunologically active substance onto natural or synthetic microparticles, agglutinating the microparticles in a liquid medium in the presence of an immunologically reactive substance of clinical interest, and optically measuring the agglutinated substances to determine the assay of the immunological reactive substance of clinical interest. The device employed for carrying out the above method includes a first series of tubes which contain at least one freeze-dried calibration range of the substance to be assayed, a second series of tubes which contain an immunological active substance acting as the assaying agent, and a third series of small tubes containing a freeze-dried specimen of the dilution solution of the calibration range.

Abstract: Patients suffering from HIV-1 infection, including both those who have and those who have not developed acquired immunodeficiency syndrome, are treated by extracorporeal removal of IgG and immune complexes. An immunoadsorbent material for removing IgG and IgG-complexes from biological fluids is prepared by covalently binding protein A to a solid-phase silica matrix. It has been found that particularly stable, high-capacity immunoadsorbents are obtained by derivatizing the silica with amino and/or carboxyl groups, and reacting the protein A with a carbodiimide at a pH in a range from 3.5 to 4.5. Binding through free hydroxyl groups may be achieved with cyanogen halides at a pH in the range from 11.0 to 11.5. After acid washing (pH 2.0-2.5) to remove non-covalently bound protein A, the immunoadsorbent may be employed in a column for therapeutic treatment of various cancers and autoimmune disorders where IgG-complexes are implicated as suppressing factors in inhibiting a normal immune response.