Abstract: The present invention is directed to fluorescent dyes and its valence tautomers of the formula wherein Q represents a conjugated moiety that increases the fluorescent quantum yield of the compound; R.sub.1 is a functionalized group of the formula--(CH.sub.2).sub.j Y, wherein Y is selected from the group consisting of SO.sub.3 H, COOH, NH.sub.2, CHO, NCS, epoxy, phthalimido, and COOZ, wherein Z represents a leaving group; R.sub.2 is a functionalized group of the formula --(CH.sub.2).sub.k Y', wherein Y' is selected from the group consisting of SO.sub.3 H, COOH, NH.sub.2, CHO, NCS, epoxy, phthalimido, and COOZ, wherein Z represents a leaving group; M.sup.+ is a counterion selected from the group consisting of ammonium, alkali metal cations, and alkaline earth metal cations; n=1 to 4; m=1 to 4; j=2 to 10; and k=2 to 10.

Abstract: An assay for the identification of neutralizing botulinum antibodies in sera is provided which includes the steps of separating non-sodium dodecyl sulfate, non-trypsinized complex botulinum toxin in an arylamide gel by electrophoresis, the separation occurring on a basis of botulinum toxin protein size and charge. Thereafter, the separated protein is electrophoretically transferred onto a solid support, the transferred separated protein being bound to the solid support at spaced apart sites. Remaining sites on the solid support not occupied by bound protein are blocked and the solid support and bound protein are contacted with a sera sample containing an antibody directed against botulinum toxin. The contacted solid support is then exposed to a second antibody capable of reacting to produce an insoluble colored substrate of intensity relative to a quantity of antibodies present. Finally, the second antibody is reacted to produce the insoluble colored substrate which is visually identified.

Abstract: The superparamagnetic monodispersed particles comprise a core of a first polymer, an internal layer of a second polymer coating the core and in which a magnetic material is distributed, and an external layer of a third polymer coating the magnetic layer and capable of interacting with at least one biological molecule. At least the second polymer is heat sensitive and has a predetermined lower critical solubility temperature (LCST) of 15-65.degree. C. These particles may be used to isolate at least one biological molecule from a liquid specimen.

Abstract: A reagent useful in immunoassays, comprising a direct particulate level co-sensitized with a specific binding agent having specificity for an analyte or analyte analog and with a non-specific protein which can participate in a control reaction with another specific binding agent which does not bind to the first specific binding agent nor participate in the formation of a complex by means of which detection of the analyte or analyte analog is accomplished. Preferably the first specific binding agent is an antibody raised in a first species and the non-specific protein is an immunoglobulin from another species. Optionally, the reagent additionally comprises a second population of the direct particulate label sensitized solely with the non-specific protein.

Abstract: The present invention describes xanthene dyes, including rhodamines, rhodols and fluoresceins that are substituted one or more times by a sulfonic acid or a salt of a sulfonic acid. The dyes of the invention, including chemically reactive dyes and dye-conjugates are useful as fluorescent probes, particularly in biological samples.

Abstract: The invention provides a biocompatible polymeric coating material, wherein the polymeric material is selected from the group consisting of linear, dendrimeric and branched polymers which contain primary, secondary, tertiary or quaternary amine groups with hydrophobic side chains and which polymers are insoluble, or only slightly soluble, in aqueous solution at a pH range between 3 and 11 and soluble in at least one organic solvent selected from the group consisting of alcohols, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexanes and mixtures thereof.

Abstract: A technique is disclosed for generating nonrandom combinatorial libraries on solid phase supports in which each of a set of predetermined species of test compounds is present on a predetermined number of solid phase supports, preferably on only one, and each solid phase support has only a single species of test compound. Each of the predetermined species of test compounds is prepared with absolute certainty because the technique does not employ any random division of the solid phase supports. Rather, the method is based on the stepwise division of a continuous solid phase support matrix prior to each synthetic step in which more than one type of subunit is added. Non-limiting examples of matrices of the solid phase supports include polypropylene membranes, polytetrafluoropropylene membranes and cotton thread. The combinatorial libraries made by the technique are also disclosed.

Abstract: An arrangement for the investigation of hydrophilic macromolecules (1) in an aqueous solution having a solid carrier surface (5) onto which a lipid film (24) is disposed, wherein the molecules (1) to be investigated are bound, by means of a molecular coupling system (20), to the lipid film (24) and thus are immobilized, is characterized in that the molecular coupling system (20) comprises at least two, preferably three molecular or nuclear components (21, 22, 23), which can be coupled to each other, of which a first component (21) is bound to the lipid film (24) and a second component (22) is bound to a hydrophilic macromolecule (1) to be investigated. In this way, it is rendered possible to immobilize and investigate any hydrophilic macromolecules, wherein the coating of the solid carrier surface should be able to be carried out in an as easy as possible and reversible manner.

Abstract: A polybifunctional reagent is provided having a polymeric backbone, one or more pendent photoreactive moieties, and two or more pendent bioactive groups. The reagent can be activated to form a bulk material or can be brought into contact with the surface of a previously formed biomaterial and activated to form a coating. The pendent bioactive groups function by promoting the attachment of specific molecules or cells to the bulk material or coated surface. Bioactive groups can include proteins, peptides, carbohydrates, nucleic acids and other molecules that are capable of binding noncovalently to specific and complimentary portions of molecules or cells.

Abstract: Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

Abstract: The present invention relates to a method for the enhancement of fluorescence wherein a fluorophor is connected to a textured material. The method can be used in any forensic or medical diagnostic assay, particularly where the absence or presence of a molecule having a concentration of less than about 1 .mu.g/ml is desirably determined.

Abstract: The invention relates to synthetic calibrators for immunological tests, analyte-specific epitopes being coupled to other proteins or to synthetic carriers.

Abstract: The present invention provides internally calibrated competitive assays for use on a solid support. Additionally, the invention provides a method of using such assays.

Abstract: The invention provides a method of assessment of carbohydrate-deficient transferrin in a transferrin containing body fluid, said method comprising the steps of:i) obtaining a transferrin containing liquid sample of or derived from a said fluid;ii) contacting said sample with a source of iron ions;iii) subsequently contacting said sample with an anionic ion exchange resin at a pH such as to cause carbohydrate-deficient transferrin to be retained by said resin;iv) subsequently contacting said resin with an eluant serving to release carbohydrate-deficient transferrin into the eluate from said resin;v) collecting a volume of said eluate substantially free from tetra- and penta-sialo transferrin; andvi) assessing the transferrin variant content in said volume of eluate.By including at least a proportion of the trisialotransferrin in the eluate, it is possible to use relatively simple assessment techniques such as turbidimetry in the assay.

Abstract: The presently claimed invention relates to polymeric assemblies which visibly change color in the presence of analyte. In particular, the presently claimed invention relates to liposomes comprising a plurality of lipid monomers, which comprises a polymerizable group, a hydrophilic head group and a hydrophobic tail group, and one or more ligands. Overall carbon chain length, and polymerizable group positioning on the monomer influence color change sensitivity to analyte concentrations.

Abstract: There are electrically conductive, electroactive functionalized conjugated polymers having formula (I): ##STR1## These electrically conducive, electroactive conjugated polymers may be covalently bonded to a first biological molecule or antiligand. Polymers bonded to a first biological molecule or antiligand may be used to form an electrode and may be used to assay for, detect and/or extract a second biological molecule or ligand.

Abstract: A plasmid isolated from Clamydia trachomatis is described, which comprises 8 genes encoding proteins useful in the formulation of vaccines or diagnostic test for determining the bacterium or specific antibodies generated during C. trachomatis infections; in particular the recombinant fusion MS2-pgp3D protein is described comprising polypeptidic sequences encoded by pCT and immunogenic in the course of infections in man. A method for preparing said protein in E. coli further described.

Abstract: A multi-slide assembly includes various components that alone or in combination facilitate testing of test samples with minimal manipulation of assay components. Moreover, the various device components permit centrifugation, culturing and analysis of each test sample to be performed in the same assembly. A frame retains a plurality of reaction vessel assemblies between a pair of opposing channels that are configured to slidably receive the opposing ends of each reaction vessel assembly. A strip cap seals the openings in each reaction vessel using cap members having sealing rings circumscribing the external walls thereof to form compression seals with internal walls of the reaction vessels. Furthermore, in a method of making a multi-well slide assembly, an ultrasonic welding process removably bonds a plurality of wells to a slide plate to provide an adequate seal therebetween during centrifugation, yet still enable separation thereof by an operator.

Abstract: This invention relates to an improvement in a method for detecting labeled molecules and especially biotinylated molecules and particularly relates to a method for reducing background signal problems in such detection methods.

Abstract: A substrate for solid phase synthesis of the formula: ##STR1## is disclosed. Also disclosed are processes for preparing the substrate and intermediates useful therein. Among the novel intermediates are compounds of the formula: ##STR2## wherein t is 0 or 1; n is 3-20; R is OH, an activated ester or the residue of a solid support having a plurality of amino functionalities; A is --O-- or --NH-- and Q is hydrogen or a protecting group for an amine or alcohol.

Abstract: The invention relates to libraries of synthetic test compound attached to separate phase synthesis supports. In particular, the invention relates to libraries of synthetic test compound attached to separate phase synthesis supports that also contain coding molecules that encode the structure of the synthetic test compound. The molecules may be polymers or multiple nonpolymeric molecules. Each of the solid phase synthesis support beads contains a single type of synthetic test compound. The synthetic test compound can have backbone structures with linkages such as amide, urea, carbamate (i.e., urethane), ester, amino, sulfide, disulfide, or carbon--carbon, such as alkane and alkene, or any combination thereof. Examples of subunits suited for the different linkage chemistries are provided.

Abstract: An assay device for detection or determination of an analyte in a sample uses opposable components and is suitable for assay of human chorionic gonadotropin and other protein or glycoprotein hormones.

Abstract: A method and apparatus for analyzing molecular structures within a sample substance using an array having a plurality of test sites upon which the sample substance is applied. The invention is also directed to a method and apparatus for constructing molecular arrays having a plurality of test sites. The invention allows for definitive high throughput analysis of multiple analytes in complex mixtures of sample substances. A combinatorial analysis process is described that results in the creation of an array of integrated chemical devices. These devices operate in parallel, each unit providing specific sets of data that, when taken as a whole, give a complete answer for a defined experiment. This approach is uniquely capable of rapidly providing a high density of information from limited amounts of sample in a cost-effective manner.

Abstract: The invention relates to methods of performing a binding assay for an analyte of interest present in a sample based upon electrochemiluminescence at an electrode of interest. Particles are employed in the method, which are then collected in a zone at which electrochemiluminescence can be induced, wherein the amount of induced electrochemiluminescence is related to the amount of analyte in the sample.

Abstract: A stable protein-coated nickel particle useful in biological assays contains a nickel particle having removed from the surface thereof nickel oxide; a linker attached to said nickel particle, the linker having a free amino group; and a protein attached to said linker by covalently bonding to the free amino group. Methods of producing and using these oxide-free nickel-protein conjugates are disclosed.

Abstract: A mixture of recombinant mono- and poly-epitope proteic materials able to fully replace the viral antigens when used in an enzyme immunoassay (EIA) is disclosed; the mixture includes a poly-epitope fusion protein having a first region formed by an amino acid sequence (H10) corresponding to that of the last 233 amino acids of the COOH terminus of the viral protein p52 or to a part thereof, a second region formed by an amino acid sequence (F3) corresponding to that of the last 43 amino acids of the COOH terminus of viral protein pp150 or to a part thereof, and a third region formed by an amino acid sequence (A1C2) corresponding to that taken from aa 595 to aa 614, proceeding in direction 5'.fwdarw.3', of the same viral protein pp150; and, in combination, a second fusion protein including a sequence of amino acids corresponding to that taken, proceeding in direction 5'.fwdarw.

Abstract: Disclosed is a sensor for sensing the presence of an analyte component without relying on redox mediators. This sensor includes (a) a plurality of conductive polymer strands each having at least a first end and a second end and each aligned in a substantially common orientation; (b) a plurality of molecular recognition headgroups having an affinity for the analyte component and being attached to the first ends of the conductive polymer strands; and (c) an electrode substrate attached to the conductive polymer strands at the second ends. The electrode substrate is capable of reporting to an electronic circuit reception of mobile charge carriers (electrons or holes) from the conductive polymer strands. The electrode substrate may be a photovoltaic diode.Also disclosed is method of forming a sensor capable of sensing the presence of an analyte component. This method includes (a) contacting a sensor substrate (e.g.

Abstract: The present invention relates to methods for substantially reducing adsorption of at least one positively charged molecule to a negatively charged surface upon contact therebetween, the method comprising combining the positively charged molecule with at least one blocking agent in an amount sufficient to substantially reduce the adsorption of the positively charged molecule to the negatively charged surface.

Abstract: A type IV collagen high molecular form having a higher molecular weight than the 7S domain of type IV collagen and including the 7S domain in its structure, is obtained from the supernatant being recovered from a collagen solution digested by pepsin in the following steps;1) salt precipitating with sodium chloride at a concentration no higher than 1.2 M,2) dissolving the precipitates,3) salt precipitating with sodium chloride at a concentration no higher than previous concentration. By reacting a sample with an antibody which reacts with this form, the type IV collagen high molecular form in the sample can be measured to allow diagnosis of the degree of liver fibrosis in patients with liver diseases.

Abstract: A method of measuring the amount of cyclosporin in a sample suspected of containing cyclosporin is disclosed. A method of inactivating interfering cross-reactive material in an assay for measuring the amount of cyclosporin in a sample suspected of containing cyclosporin is also disclosed. Compositions wherein cyclosporin is conjugated to an immunogenic carrier or a label, optionally through a linking group, at an alanine nitrogen atom of the cyclic backbone of cyclosporin are also disclosed. Compositions wherein atiocyclosporin is conjugated, optionally through a linking group, to an immunogenic carrier or a label are also disclosed. Where cyclosporin is conjugated to an immunogenic carrier, the conjugates may be used as immunogens for the preparation of antibodies which are capable of recognizing cyclosporin.

Abstract: Sensor laminates for detection by immunoassay of target molecules in biological fluids wherein the sensor laminates contain a reactive substrate layer having a polymeric material treated to enhance binding to a ligand and methods of producing and using these sensor laminates are provided. Also provided are multi-sectioned fluid delivery devices for use with the sensor laminates in detection of target molecules in biological fluids.

Abstract: This disclosure relates to novel antibodies specific to the recently discovered receptor to human interleukin 12 (IL-12R). The antibodies to IL-12R, most preferably, the monoclonal antibodies to that protein, are useful in determining the status of the human immune system and as diagnostic reagents or potential therapeutic reagents for conditions involving imbalances in IL-12 levels or cell types sensitive to IL-12 activation.Further aspects of the disclosure relate to methods of producing and purifying such novel antibodies and hybridoma cell lines capable of their production. Another aspect of the disclosure relates to an immunoprecipitation assay for the detection of solubilized IL-12R which employs, in a preferred embodiment, monoclonal antibodies to the receptor of the present invention covalently bound to Protein G-Sepharose resin.

Abstract: The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems.

Abstract: The invention provides a monospecific antibody that is specifically reactive with enzymatically mediated degradation products of fibrin(ogen) (i.e., fibrin, fibrinogen, and related substances). The monospecific antibody of the invention is specifically reactive with an epitope defined by an amino acid sequence SEQ ID NO:1. The invention further provides compositions containing a monospecific antibody, optionally detectably labeled, for the performance of fibrinolytic or thrombolytic analyses. The invention further provides continuous cell lines (hybridomas) that produce monospecific antibodies as described.

Abstract: In a vertical down-flow fluid bed reactor, suspended particles in liquid proximal to an inlet in an uppermost part of the reactor are agitated to form a downward extending turbulent zone having vigorously moving particles and a non-turbulent zone distal to the inlet having essentially stationary particles in liquid below and adjoining the turbulent zone. In a vertical up-flow fluid bed reactor, an upward extending turbulent zone is formed proximal to an inlet in a lowermost part of the reactor and the non-turbulent zone is above the turbulent zone. The downward or upward extend of the turbulent zone is determined by the degree of agitation. The particles may contain an active substance and be in the form of a conglomerate of base particles having a desired density to control floatation or sedimentation. Particles in the turbulent and non-turbulent zones may be different such as having different specific gravities.

Abstract: An improved multi-layered diagnostic sanitary test strip for receiving a heterogenous fluid, such as whole blood, to test for presence and/or amount of a suspected analyte in the fluid by facilitating a color change in the strip corresponding to the amount of the analyte in the fluid, wherein the test strip includes fluid volume control dams to prevent spillage of the fluid from the strip and a chemical reagent solution that facilitates end-point testing. The improved test strip comprises (a) an upper support strip having a fluid receiving port and (b) a lower support strip having a color change viewing port and securely sandwiched therebetween (c) a spreading mesh screen for uniformly distributing the fluid, (d) a chemically treated separating layer for removing an undesirable element, e.g.

Abstract: An immunoassay method in which blood can be measured even without pretreatment by a centrifuge etc. In the present invention, antibodies or antigens in a sample are subjected to agglutination reaction with insoluble carriers onto which antigens or antibodies specifically reacting with the antibodies or antigens in the sample have been imrobilized and the resulting agglutination mixture is determined for the change in its absorbance or in its scattered light by irradiation with light, wherein said sample is whole blood and the whole blood is forcibly lysed.

Abstract: Described is a method for differentiating the vaginal secretory fluid or cervical mucus of a pregnant woman suffering from threatened premature delivery, which comprises measuring an amount of Interleukin-8 in the vaginal secretory fluid or cervical mucus. The above method makes it possible to differentiate the vaginal secretory fluid or the like of the pregnant woman suffering from threatened premature delivery with good sensitivity and therefore is useful for the detection, treatment or the like of premature delivery.

Abstract: A method for detecting mutations, such as a single base change or an addition or deletion of about one to four base pairs, is based on the use of an immobilized DNA mismatch-binding protein, such as MutS, which binds to a nucleic acid hybrid having a single base mismatch or unpaired base or bases, thereby allowing the detection of mutations involving as little as one base change in a nucleotide sequence. Such a method is useful for diagnosing a variety of important disease states or susceptibilities, detecting the presence of a mutated oncogene and for isolating or removing by affinity chromatography duplex DNA molecules containing mismatches such as error-containing molecules in PCR-amplified DNA samples. Also provided are kits useful for practicing the methods of the present invention.

Abstract: Methods of calculating the platelet count of an individual, by measuring the amount of a released platelet granule protein of interest in a sample of whole blood or of platelet-rich plasma from the individual, are described. The platelet granule protein of interest is either thrombospondin or .beta.-thromboglobulin. The amount of released platelet granule protein of interest in the whole blood sample or platelet-rich plasma sample is measured using an enzyme-linked immunosorbent assay; radioimmunoassay; sandwich assay; a quantitative immunochromatographic assay; or non-solid phase nephelometry. The platelet count is directly related to the amount of released platelet granule protein of interest in the sample, and can be determined from the amount of platelet granule protein of interest that is released from a known number of platelets.

Abstract: An immunoassay test kit including an immunological binding partner that binds to lysyl pyridinoline, for analyzing a body fluid sample for bone resorption in vivo.

Abstract: The use of a phycobiliprotein-linker peptide complex as a fluorescent tracer in a fluorescent method of detecting and/or determining an analyte in a medium in which it may be present, is disclosed. Fluorescent conjugates consisting of said complex covalently bonded to one of the elements of a ligand/receptor specific binding pair, are also disclosed.

Abstract: Methods are provided for forming a coating of an immobilized biomolecule on a surface of a medical device to impart improved biocompatibility for contacting tissue and bodily fluids. A 2-aminoalcohol moiety of a biomolecule is oxidized with a periodate to an aldehyde moiety which is reacted with an amine moiety on the surface of a medical device to form an imine moiety, and the imine moiety is reduced to form an amine linkage immobilizing a coating of the biomolecule on the surface. Conversely, the biomolecule can contain the amine moiety and the 2-aminoalcohol moiety can be on the surface. In another method, a biomolecule coating containing an amine moiety and a 2-aminoalcohol moiety is immobilized on the surface of a medical device, and the 2-aminoalcohol moiety is oxidized with a periodate to an aldehyde moiety which reacts with the amine moiety to crosslink the coating.

Abstract: A self-addressable, self-assembling microelectronic device is designed and fabricated to actively carry out and control multi-step and multiplex molecular biological reactions in microscopic formats. These reactions include nucleic acid hybridizations, antibody/antigen reactions, diagnostics, and biopolymer synthesis. The device can be fabricated using both microlithographic and micro-machining techniques. The device can electronically control the transport and attachment of specific binding entities to specific micro-locations. The specific binding entities include molecular biological molecules such as nucleic acids and polypeptides. The device can subsequently control the transport and reaction of analytes or reactants at the addressed specific micro-locations. The device is able to concentrate analytes and reactants, remove non-specifically bound molecules, provide stringency control for DNA hybridization reactions, and improve the detection of analytes. The device can be electronically replicated.

Abstract: A material is provided for immobilization of biologically active substances which are reactive with a carbodiimide group. The material contains a carbodiimide group-containing polymer supported on a carrier such as a plastic, an inorganic polymer, a metal, a natural polymer or a ceramic. The carbodiimide group-containing polymer has 2 to 100 carbodiimide groups per molecule and a molecular weight of 1,000 to 100,000, and is prepared by carbodiimidization of an organic polyisocyanate in the presence of a catalyst. The polymer may be supported as a film on part or the whole area of the carrier. Biologically active substances that may be immobilized include enzymes, hormones, antibodies, antigens, heptenes, peptides, DNAs and RNAs.

Abstract: Combinatorial libraries are disclosed which are represented by Formula I: ##STR1## wherein: ##STR2## is a solid support; T'--L-- is an identifier residue; and --L'--II' is a ligand/linker residue. These libraries contain dihydrobenzopyrans of the formula ##STR3## which interact (i.e., as agonists or antagonists) with .alpha. adrenergic receptors, dopamine receptors, .sigma.-opiate receptors, and K.sup.+ channels and are inhibitors of carbonic anhydrase isozymes. They are useful in the treatment of ocular diseases such as glaucoma.

Abstract: A method for identifying a toxicant in an environmental water or soil sample comprising (a) adding to the sample an antibody known to form a complex with a toxicant suspected to be present in the sample; (b) incubating the antibody with the sample for a time and under conditions sufficient to allow complexes to form between the antibody and the toxicant; and (c) comparing the toxicity of the sample treated as in the step (b) with the toxicity of the sample prior to the step (a), whereby a reduced amount of toxicity of the treated sample compared with the untreated sample indicates the presence of the toxicant in said sample. The method described herein provides unexpected and important advantages by providing more accurate correlations between predicted and observed toxicity of a sample than previous methods.

Abstract: The present invention relates to a method of carrying out an immunoassay in a multiphase system. Particularly, a sample containing an analyte is brought into contact with a receptor A and a tracer. The analyte can either from a complex with the tracer, or counteract the formation of a complex of receptor A and tracer by competing with the tracer for binding to receptor A, or counteract the formation of a complex of receptor A and tracer by competing with receptor A. Receptor B is added and the signal is determined. In this method, receptor A and receptor B are suitably immobilized, ensuring that the tracer either cannot enter into any binding involving the simultaneous participation of receptors A and B or can enter into such a binding to only such a slight extent that it is nevertheless possible to detect and differentiate differing analyte concentrations.

Abstract: This invention provides a novel process of using magnetically responsive fluorescent polymer particles comprising polymeric core particles coated evenly with a layer of polymer containing magnetically responsive metal oxide as highly sensitive quantitative reagents for biochemical and immunological studies, wherein the fluorescent magnetic particles can serve as a marker for the number of particles. A wide variety of polymeric particles with sizes ranging from 1 to 100 microns can be used a core particles and transformed into magnetically responsive polymer particles. The surface of these magnetically responsive polymer particles can be coated further with another layer of functionalized polymer.

Abstract: The patent application describes a sandwich-type immunoassay for the detection and/or quantitation of collagen degradation products in biological samples such as blood, serum, plasma, sputum and cell cultures. The immunoassay uses a first antibody directed at an epitope present on a collagen molecule at a distance of up to 165 amino acids from a collagen telopeptide crosslink site, and a second antibody directed at another epitope of the crosslinked collagen molecule.