MXPA97003738A - Method of immunological determination using oligomerize receptors - Google Patents

Abstract

The present invention relates to that in order to extend the range of measurement and reduce the Hook effect (hook effect) in an immunological method of determining an antigen based on the principle of an interposition or sandwich assay, it is preferred to use a method which is characterized in that the labeled detection molecule is an oligomer of a binding or binding molecule selected from the antibody and / or antibody fragment

Description

METHOD OF DETERMINATION USING OLIGOMERIZED RECEIVERS FIELD OF THE INVENTION The present invention relates to a method for the immunological determination of an anaiits according to the interposition or intercalation test principle and suitable binding substances for this. In particular, the invention relates to an improvement of such methods of intercalation or interposition for extend the range of measurement and reduce the effect of Hook (hook effect).

BACKGROUND OF THE INVENTION The quantitative determination of antigenic substances by means of immunoassays is known. An interposing or so-called sandwich test is often used for this, in which two antibodies directed to the same or different epitopes of the analyte are incubated with a sample containing an analyte to be determined. In this method a soluble first antibody is coupled directly or indirectly to a system that generates a signal, ie a label or brand REF: 24683 while a second antibody (in a heterogeneous assay) is coupled to a solid phase or provided with a binder component such as, for example, biotin which is capable of binding or binding to an appropriately coated solid phase. The concentration of a number of important proteins in the diagnosis can vary within a wide range that proposes a wide range of measurement is desirable or even essential for the analytical. Examples of such proteins are, for example, cancer parameters such as Ot fetoprotein (AFP) and carcinoembryonic antigens (CEA) and also the human chlorogenic gonadotropin of pregnancy protein (HCG). When such analytes are determined it is important in the diagnosis on the one hand to obtain an exact value in high concentration ranges to be able to perform a successful monitoring, but on the other hand it should also be possible to make an accurate determination in the lower concentration range for a qualitatively correct diagnosis (yes / no) which in turn can lead to fundamental therapeutic consequences. A problem with high analyte concentrations in a sample to be examined is the so-called "hook effect" which is understood as a decrease in the detectable signal at very high analyte concentrations. The reason for this is that normally in a heterogeneous interposition assay format the soluble antibody and the solid phase antibody are present in an excess relative to the analyte to be determined so that the interposition complexes can be formed and also detected in the form essentially complete; however, in the case of a high analyte concentration a limited number of antibodies is faced with a very large number of analyte molecules. In the extreme case there is a deficit of solid-phase antibody so that the analyte binds only partially and in addition the analyte fraction bound to the solid phase can not be completely detected since the labeled antibody is captured by the excess of analyte with formation of soluble detection antibodies: analyte complexes. This results in a reduction of the measured signal which can lead to a false, false test result. A solution to the problem is, of course, to properly dilute the sample to be examined. However, since in practice it is not known from the beginning when and to what extent a dilution has been made, this means that several measurements with different concentrations have to be carried out which is undesirable for reasons of costs and because of the increased amount of work. An additional solution to this problem is to increase the concentration of both antibodies used in the intercalation or interposition assay. This however, results in a number of disadvantages such as for example additional interference possibilities., a high target value and an unfavorable form of the calibration curve. In addition, the costs of each individual determination are also increased so that this possibility also can not be seen as satisfactory. Still an additional solution is described in US Pat. No. 4,743,542. This patent teaches that the calibration curve can be linearized at high analyte concentrations by the addition of unlabelled first or second antibodies or mixtures thereof. This decreases the sensitivity in the lower measurement range but increases it to higher analyte concentrations resulting in full or complete linearization of the calibration curve. However, a disadvantage of the method according to US Patent No. 4,743,542 is the reduction of the sensitivity in the lower measurement range. This reduction is particularly critical when a precise test result is essential in the lower measurement range eg in the HCG test to determine whether a pregnancy is present or not.

DESCRIPTION OF THE INVENTION Therefore, the object of the invention was to provide a method for the immunological determination of an analyte in which the disadvantages of the state of the art are at least partially eliminated and which in particular allow a quantitatively accurate determination over a wide range of measurement while At the same time good results are obtained in the lower concentration range. This object is achieved according to the invention by a method for the immunological determination of an analyte in a sample liquid according to the principle of an interposition test in which the sample liquid is incubated in the presence of a solid phase with at least two receptors capable of binding or linking to the analyte to be determined in which the first receptor is soluble and the second receptor (a) binds to a solid phase or (b) is capable of binding to a solid phase and the analyte is detected by determining the label or label in the solid phase and / or in the liquid phase which is characterized in that the first receptor is an oligomer of a binding or binding molecule selected from antibodies, antibody fragments and mixtures of the same. It has surprisingly been presented that the use of a soluble oligomeric antibody allows the Hook effect to be reduced and consequently an extension of the measuring range. In general, the sensitivity in the lower measuring range is retained or even improved. The lower detection limit LLD according to Kayser (Fresenius "Zeitschrift für analytische Chemie", volume 209, number 1, page 1-18, 1965) is used in the present description as a measure of the sensitivity in the lower measurement range . The first receptor used according to the invention is an oligomer of a binding molecule or binder selected from antibodies and / or antibody fragments and for the sake of simplicity is referred to as "oligomeric antibody" in the following. The prefix "first" or "second" antibody only serves the purpose of distinction in this description and not for instances related to an order of addition, etc. The term "antibody" in the present invention is understood as an antibody with a unique or single specificity such as a monoclonal antibody as well as a mixture of antibodies that target different epitopes of the same antigen such as a polyclonal antiserum. "Antibody fragment" is understood as any molecule that is derived from a complete antibody while retaining at least one paratope and which for example can be obtained by enzymatic or chemical treatment of an antibody or by genetic engineering. In particular, a fragment of F (ab ') - is understood as an antibody fragment. The degree of oligomerization relative to a whole antibody or fragment of F (ab ') 2 is at least two, that is, the minimum number of paratopes of an oligomeric antibody according to the invention is four. The minimum degree of oligomerization is preferably two to three.

The maximum degree of oligomerization is up to 15, preferably up to 10, and more preferably up to 8. The degree of oligomerization is more preferably 2 to 8 and especially preferably 4 to 6. The first oligomeric receptor is preferably used. in a form labeled or marked in the method according to the invention. This means that it is coupled or linked directly or indirectly to a marking or labeling group. In this connection a direct coupling is understood as a covalent incorporation of a detectable substance or of a molecule which in reaction with a suitable substrate generates a detectable substance. An example of the latter could be for example an enzyme which binds or binds covalently to the receptor optionally via an intermediate or separator. An indirect coupling denotes a configuration in which the first receptor according to the present invention and a detectable substance or a molecule generating such a substance, are able to bind or bind to each other via a specific agglutination or binding pair such as biotin / avidin. The marking or labeling group in the method according to the invention can be selected from labels or marks known in the state of the art. Examples are radiolabels and labels or or enzyme labels or labels or luminescent labels. Preferred examples of labels or enzyme labels are for example alkaline phosphatase, peroxidase and galactosidase. Preferred as the luminescent tags or labels are the photoproteins that can be activated by calcium such as acuorin and labels or electrochemiluminescent labels. Labels or labels in which the determination is by means of a luminescent reaction, are especially preferred, and a group of labeling or labeling of luminescent metal chelate is more preferred as the labeling or labeling group. The luminescent metal chelates are metal chelates that generate a detectable luminescence reaction. The detection of this luminescent reaction can be, for example, by fluorescence measurement or by electrochemiluminescence. The metal of these metal or metal chelates is for example a transition metal or a rare earth metal. The metal is preferably ruthenium, osmium, rhenium, iridium, rhodium, platinum, indium, palladium, molybdenum, tecnetium, copper, chromium or tungsten.

Ruthenium, rhenium, iridium and osmium are particularly preferred and ruthenium is more preferred. The ligands which form the metal chelate together with the metal are usually polydentate ligands, ie, ligands with various coordination positions. Polydentate ligands, for example, comprise aromatic and aliphatic ligands. Suitable aromatic polydentate ligands include aromatic heterocyclic ligands. Preferred heterocyclic ligands are N-containing polyheterocycles such as, for example, bipyrididyl, bipyracil, terpyridyl and phenanthrolyl. These ligands may contain, for example, substituents such as alkyl, substituted alkyl, aryl, substituted aryl, aralkyl, carboxylate, carboxyaldehyde, carboxamide, cyano, amino, hydroxy, imino, hydroxycarbonyl, aminocarbonyl, amidine, guanidino, ureide, groups containing sulfur, phosphorus-containing groups and the N-hydroxysuccinimide carboxylate esters. The chelate may also contain one or more monodentate ligands. Examples of monodentate ligands include carbon monoxide, cyanides, isocyanides, halides and amines, stilbenes, arsines and aliphatic, aromatic and heterocyclic phosphines.

The luminescent metal chelate is in particular preferably selected from metal chelates containing phenanthrolyl or bipyridyl ligands. Examples of suitable metal chelates and the production thereof are described in patent applications EP-A-0 178 450, EP-A-0 255 534, EP-A-0 580 979 and WO 90/05301. The reference is made here to this description. The most preferred metal chelates are ruthenium- (bipyridyl) chelates. These chelates are commercially available in the form of active ester derivatives for example, from Igen Inc. (Rockville, MD, USA). The tagged or labeled receiver used in the method according to the invention contains one or more tagging or tagging groups. If several labeling or labeling groups are used per molecule of the first oligomeric receptor, it is preferred that the number of labeling or labeling groups be from 2 to 20 and more preferably from more than 2 to 10. The second receptor used in the The method according to the invention binds or binds to the solid phase or is capable of binding thereto. The term "linked or bound to the solid phase" is understood in this description as an immobilization that takes place before the assay by binding or binding to a macromolecular carrier such as by adsorption, binding or covalent attachment or by means of a pair of specific link or union. According to the term "capable of binding" it is understood as an immobilization during the assay by means of the specific interaction of a suitable specific binding pair such as biotin / avidin. The second receptor is preferably coupled or linked to the solid phase by means of a specific binding pair. The second receptor is particularly biotinylated in preferred form and the solid phase is coated with avidin or / and streptavidin. The type of the second receptor is not particularly critical in the method of the present invention and therefore the second receptor can be selected from a number of molecules as long as they can specifically bind to the analyte to be determined. Examples of substances that are suitable for use as a second receptor are, for example, oligomeric antibodies within the meaning of this invention, antibodies, antibody fragments, cell or cell receptors, enzymes, nucleic acids and other substances which due to A particular spatial structure, or chemical affinity, are capable of binding or binding to the analyte to be determined. Depending on the exact experimental design, conventional solid phases are used as the solid phase in the method according to the invention. This for example comprises finely dispersed materials such as polystyrene beads or material particulate magnetic and in general surfaces of reaction vessels such as the wall of a cuvette or a microtitre plate and for special applications microplates (chips) or sensors or membranes. In the presently preferred embodiment of the method according to the invention, the solid phase is a particulate magnetic material which contains a coating capable of binding or binding to the second receptor. The exact procedure for the method according to the invention corresponds to known protocols of interposition or interleaving tests and is familiar to a person of ordinary skill in the art. In general, a sample that contains an analyte to be determined, is incubated under suitable conditions and for an appropriate period of time with a first receptor, second receptor and solid phase in an arbitrary order to ensure that an interposed or intercalated complex is formed immobilized.

Subsequently, the interposition complex containing the analyte that forms is separated from the free labeled antibody and is determined qualitatively or quantitatively in optional form after the addition of a suitable detection substrate. In a preferred embodiment of the method according to the invention, the sample to be examined is first mixed and incubated with an oligomeric antibody labeled or labeled with ruthenium chelate and a biotinylated antibody. In a second step, the magnetic beads that are coated with avidin or streptavidin are added and incubated further. After the mixture is passed over a magnet, the beads are separated ie the complex that is formed is separated from the remaining sample and the unbound or unbound labeled or labeled antibody and the separated complex is washed again with a solution that it contains a reducing agent such as tripropylamine (TPA) and optionally a surface active agent. The washing process removes all the ruthenium except what is attached in the interposition complex. The concentration of Ru measured is thus directly proportional to the analyte concentration.

• -When an electrical voltage is applied, a luminescent reaction occurs in which ruthenium and TPA react. Optionally when a first labeled receptor is used, an unlabeled specific-analyte receptor may be additionally present, for example, an oligomeric antibody and / or monomeric unlabeled antibody. According to a further aspect the present invention relates to an oligomeric antibody comprising a conjugate or set of at least two antibodies, fragments of antibodies and mixtures thereof wherein the binding or linking molecules are directly linked covalently between yes and which is characterized because the degree of oligomerization is 2 to 15. A direct link of the binding or agglutination molecules means that the antibodies or antibody fragments are linked together either via a single or simple chemical bond or via a molecule of suitable bifunctional link / separator. A large number of methods for effecting this and suitable spacer molecules are known to a person skilled in the art. For example, bis (maleinimido) -methyl ester, dimethyl suberimidate, disuccinimidyl suberate, glutardialdehyde, N-succinimidyl-3- (2-pyridyldithio) propionate, N-5-azido-2-nitrobenzoylsuccinimide, N-succinimidyl (4-iodacetyl) ) -aminobenzoate, a combination of maleinimidohexanoyl-succinimidate and S-acetyl-mercaptosuccinic acid anhydride or analogous compounds come into consideration as chemical bonds. In a preferred embodiment, the oligomeric antibody according to the invention is provided according to a first aspect of the invention with at least one and optionally several labeling or tagging groups. A luminescent metal chelate label is preferred as the label and particularly preferably the oligomeric antibody is ruthenylated / i.e., the metal or metal chelate is a ruthenium chelate. The ligands that together with the metal form the metal chelate are usually polydentate ligands, ie, ligands with various coordination positions. Such metal ligands and chelates are described, for example, in the patent application DE-A-44 30 998.8 for the disclosure of which the reference is made herewith. The most preferred metal chelates are ruthenium (bipyridyl) chelates. Yet a further aspect of the present invention is a process for the production of an oligomeric antibody which is characterized in that antibodies or / and fragments thereof are covalently linked together. For this purpose the antibody (fragments) is functionalized in a suitable manner such as by reaction with one of the bifunctional separating molecules mentioned above. Suitable reaction conditions are generally known in the state of the art and are not described in detail here (see also in Example 1). Yet a further aspect of the present invention relates to the use of an oligomeric antibody as defined above., as a detection reagent in an interposition assay. In addition, the oligomeric antibody can be used to reduce or avoid the Hook effect in an immunological method of determination. Yet a further aspect of the present invention relates to a set of reagents for the immunological determination of an analyte, which is suitable for carrying out the method according to the invention. This assembly comprises in particular an oligomeric antibody labeled as defined above and the second receptor used in the method according to the invention, ie a receptor bound to the solid phase or preferably a receptor capable of binding or binding to the solid phase for example, an antibody or / and antibody fragment. The oligomeric antibody and the second receptor can be presented separately in the set of reagents according to the invention or to each other in a single or simple reagent. The assembly optionally contains additional reagents such as a suitable solid phase, a substrate solution etc., which are then generally spatially separated. The method according to the invention is explained in more detail by the following examples.

EXAMPLES Example 1 Production of biotinylated, oligomeric and labeled antibodies 1. Biotinylated, monomeric anti-HCG antibody The monoclonal anti-HCG-M-1 F7.9 IgG (Boehringer Mannheim GmbH) is dissolved in 0.1 M potassium phosphate buffer, pH 8.4 at a concentration of 10 mg / ml. A molar amount of 6 parts of biotin-DDS * (dissolved in dimethylsulfoxide; 16.3 mg / ml) is added. After 90 minutes stirring at 25 ° C the reaction is stopped by the addition of 10 jjl 1M lysine. It is dialyzed against 25 mM potassium phosphate / 50 mM NaCl, pH 7.0 and the product is lyophilized. * Biotin (DDS) = biotinyl-amino-3,6-dioxaoctanyl-aminocarbonylheptanoic acid ester of N-hydroxysuccinimide (see DE 4302241 A1). 2. Oligomeric Rutenylated Anti-HCG Antibody a) Ruthenium labeling or labeling group The active ester Ru (bpy) 32 + -NHS ((2,2'-bipyridyl) -2- (4- [3- (N-hydroxysuccinimidyl-carboxy) propyl] -4'-methyl-2, 2'-bipyridine) ruthenium) which can be obtained from Igen Inc. Co. Rockville USA, is used to label antibodies and antibody fragments. b) Production of anti-HCG-F (ab ') 2 fragments 300 mg of the anti-HCG-M-INN22 monoclonal IgG antibody is dissociated or separated with pepsin according to Johnstone and Thorpe (Immunochemistry in Practice, page 61 f , Black ell Scientific, 1987) and fragments of F (ab ') -, are purified by S 200 chromatography. Yield or yield: 128 mg F (ab') 2- c) Production and isolation of oligomeric antibody fragments 100 mg of F (ab ') 2 anti-HCG-M-INN22 fragments are dissolved in 1.5 ml 0.15 M K-phosphate buffer, pH 8.3. Shortly before using 27.6 mg of disuccinimidilsuberate (DSS) are dissolved in 1 ml of dimethylsulfoxide. At intervals of 10 min 5 Jul of a DSS solution are added to the solution of F (ab ') -, while stirring. After a total reaction period of 75 min the crosslinking of F (ab ') 2 is stopped with 15 f. 1M of lysine solution. The crude polymer of F (ab ') 2 anti-HCG-M-INN22 is separated by gel chromatography on Sephacryl S300HR (Pharmacia, Upsala) in fractions with molecular weights of 200,000, 400,000, 500,000-800,000 and > 800,000. Polymers of = 800,000 are preferred. d) Production of rutheniated oligomeric antibody fragments mg of the anti-HCG-M-INN22 F (ab ') 2 oligomer (weight per mole of 400.00) are dissolved in 1 ml 0.15 M K-phosphate buffer, 0.15 M NaCl, pH 7.8. Immediately before the use of 5 mg of Ru (bpy), -NHS dissolve in 0.75 ml of anhydrous dimethyl sulfoxide. To obtain a molar ratio of 3.3: 1 based on molecular weights of 1057 for Ru (bpy -NHS and 100,000 for the monomer of F (ab ') 2 0.174 mg of Ru (bpy) 32 + -NHS (59.4 μl) are added by pipette to the solution of F (ab ') 2 while stirring.The reaction vessel is incubated for 60 min at 25 ° C. The reaction is terminated by adding 10 ml of a lysine solution of 1 M. The mixture is then dialysed for 24 hours for 25 mM buffer or K-phosphate buffer / 0.1 M NaCl, pH 7.0 and lyophilized Production or yield: 4.4 mg of anti-HCG-M-INN22-F oligomer ( ab ') 2 ~ Ru (bpy) 32+ (400,000) Measurement of absorbance at 455 nm (£ = 13.7) yields a ratio or molar ratio of tag or built-in mark of 2.2-2.8 = Ru: F (ab') 2. Oligomeric antibody fragments with molecular weights of 200,000 and 500,000 to 800,000 are coupled or linked in a similar manner to the labeling or ruthenium labeling groups.

Example 2 Detection of HCG using oligomeric antibodies The following two solutions containing oligomeric, labeled ruthenylated antibodies, and monomeric biotinylated antibodies are prepared: Solution 1: Antibody fragments of F (ab ') _ anti-HCG labeled with monoclonal Ru (bpy) 3 which can be obtained according to example 1, are used as the oligomeric receptor (referred to as AB-BPRU in the following) AB -BPRU is used with a degree of oligomerization of 5-7 and a degree of ruthenilation of 3.3. To prepare the solution 1 / 3.0 / - 1 / ml AB-BPRU is dissolved and mixed in 40 mmoles / 1 buffer or phosphate buffer (pH = 6.5) containing 0.1% bovine immunoglobulin (IgG) , 3.5% bovine serum albumin (BSA) and 150 mmol / l NaCl.

Solution 2: Monomeric biotinylated anti-HCG antibodies (IgG) are dissolved in a concentration of 5.0 jag / ml, degree of biotinylation = 1:10 in a buffer solution or phosphate buffer of 80 mmol / 1 (pH = 7.0) containing 0.1% of Bovine IgG, 2.0% BSA and 150 mmol NaCl. 100 μl of solution 1 and 100 _A_ L of solution 2 are mixed, 25 μl of the sample to be analyzed (human serum) are added and the mixture is incubated for 5 min at 37 ° C. Then, 35 μl of a suspension of streptavidin coated beads with an iron core, agglomeration capacity or biotin binding of 450 to 650 ng / ml, concentration of the 720 μg / ml solution are added and incubated for 5 minutes. additional min. The beads are subsequently separated, washed with a solution containing tripropylamine and electrochemiluminescence is determined. In general streptavidin Dynabeads M-280 (Dynal A.S., Oslo, Norway) is used. in the examples as beads ie, superparamagnetic polystyrene particles with a diameter of 2.8 / -un to which the streptavidin binds or binds covalently. The result is that a measurement range of up to 12,000 mlU / ml of HCG is obtained and a sample containing 500,000 mlU / ml of HCG is recognized as exceeding the measurement range (Hook effect). The lower detection limit is «0.1 mlU / ml of HCG. In this application the measurement range refers to the range in which undiluted human sera can be correctly determined.

Example 3: Influence of the degree of oligomerization in the measuring range The experimental procedure was as described in Example 2, 3.13 > u-g / ml of AB-BPRU used in solution 1 which differ in their degrees of oligomerization as follows: P1 MW 800,000 P2 500,000 - 800,000 P3 400,000 P4 200,000 P5 100,000 (= F (ab ') 2 The results are shown in Table 1. It can be seen that as the degree of crosslinking increases (= molecular weight) the signals of the higher standards increase while the target value (zero standard signal a) remains constant. Accordingly, the sensitivity of the test is increased, i.e., the increase in the degree of oligomerization leads to a wider range of measurement while the lower limit of detection is delayed.

Table 1 cr.

Example 4: Detection of HCG using a monomeric monoclonal antibody (comparison), addition of unlabeled or labeled antibody In this example in accordance with the method of U.S. Patent No. 4,743,542 a monomeric monoclonal antibody MAB < HCG > -BPRU with a degree of ruthenilation of 1: 8 is used at a concentration of 2 < -g / ml in solution 1 and the biotinylated monoclonal antibody in solution 2 is used at a concentration of 2 / j-g / ml. In addition to different amounts (2, 4, 8 and 16 -Atg / ml) of an unlabeled monoclonal monoclonal anti-HOG antibody are added to the test solution so that this antibody is present in the test mixture at concentrations of 2, 4, 8 and 16 > / ml. 3 human sera with different concentrations of HCG are tested, HS1 (2941 mlU / ml), HS2 (50,000 mlU / ml) and HS3 (500,000 mlU / ml, Hook sample) thus 2 standards that They contain 0.0 (standard a) and 13.0 mlU / ml (standard b) of HCG. The results are summarized in Table 2.

Table 2 Monomeric anti-HCG antibody without labeling [* g / ml] 2 4 8 16 increment in range = 1.0 1.84 2.76 4.19 measurement * standard b / standard to 1.89 1.77 1.58 1.44 * Ratio of the measurement range to the respective unlabeled or unlabeled antibody concentration divided by the measurement range with 2 / -v-g / ml of ~ unlabeled or unlabeled antibody.

It has been found that the measurement range is increased with an increased amount of unlabeled antibody. At the same time the standard b signal decreases as well as that of the other human sera while that of the standard a (zero serum, target value) remains essentially constant. Consequently, there is a growing unfavorable evolution of the differentiation in the lower part of the measuring range. The quotient of the b / a standard that must be at least in the range of 1.9 to 2.0 for a reliable diagnosis is already under this value when 2; ug / ml of unlabelled or unlabelled antibody is added. An affirmation about a possible pregnancy can not be made.

Example 5: Detection of HCG with monomeric polyclonal antibody (comparison), addition of unlabeled or unlabelled antibody The procedure is as in Example 4, except that the polybonal antibody PAB ^ - £ -HCG > S- (PA) -IgG (DE) is used as the unlabeled antibody. The results correspond essentially to those of Example 4, but the measuring range is only increased by a factor of 1.35. Reliable differentiation is not possible in the lower signal range. The standard b / a quotient was 1.33 when 2 > tg / ml unlabelled or unlabeled PAB was added and decreased further to higher PAB concentrations (16 -g / ml: b / a = 0.94) Example 6: Detection of HCG with oligomeric monoclonal antibody addition of unlabeled or unlabeled antibody The method is according to example 2 in which a ruthenolyzed oligomeric antibody (degree of oligomerization ca. 4-8) according to the invention, it was used as the detection antibody at a concentration of 1, 2 and 4. ug / ml. The results are summarized in Table 3.

Table 3 ruthenilated oligomeric anti-HCG antibody [? -g / p? l] 1 2 4 increment of the range of = 1.0 1.83 4.19 measurement * standard b / standard to 3.07 1.98 2.24 * Ratio of the measurement range to the respective concentration of unlabeled antibody divided by the measurement range with 1 -AA-g / ml of unlabeled or unlabeled antibody.

The target or target value (standard a) as well as the signal level of the other samples (human sera and standards) is increased with an increasing AB-BPRU concentration. As can be seen from the table the standard b / a quotient remains at or above 2.0 and therefore ensures a good measurement in the lower concentration range. At the same time, the measurement range increases considerably with an increasing AB-BPRU concentration, which in the present example arrives almost proportionally (a doubling of the antibody concentration corresponds approximately to a doubling of the measurement range). Since the measuring range is increased while the accuracy of the measurement or measurement is retained in the lower HCG concentration range, in this case there is a real extension of the measurement range for a complete estimate.

Example 7: TSH detection Comparison of monomeric and oligomeric monoclonal antibody The TSH test is used to diagnose thyroid function. The TSH values increased as well as greatly reduced in the serum are of importance in the diagnosis. For this reason a high precision of the test is also important in the lower range as well as a good differentiation between the standard to lower and the lower second b. The ratio e / a, the quotient of the highest divided by the lowest standard, serves as a parameter for the complete measurement range. The quotient should be as high as possible. The following reagents were used in a system similar to that used for HCG: R1: phosphate buffer or buffer, 50 mmol, pH = 7.4; 0.1% each of MIT and oxyperoin (for preservation), 2% bovine serum albumin, 1% bovine IgG and ruthenilated monoclonal antibody MAB-SH > -m-Fab-BP-Ru at a concentration of 2.0 Og / ml for the oligomer and 0.2 - 1.0 tg / ml for the monomer.

R2: Reagent as in R1, biotinylated monomeric antibody MAB «CTSH > F (ab ') b-Bi (DDS) is used in place of MAB-BPRU at a concentration of 1.7 yug / ml.

Pearls: Microparticles with an iron core are used having a binding capacity or biotin binding of 700 / Ag / ml.

The reaction is performed by pipetting or pipetting together 70 μl of sample, 80 μl of R1 and 80 μl of R2, carefully mixing and incubation for 10 min. After 50 AI of beads are added and incubated for about 10 min. additional After the reaction mixture is placed on the electrode as described for HCG, the microparticles are fastened with the aid of a magnet or magnet and washed. This is continued by the electrochemical reaction in which the light signal is measured quantitatively. The result is shown in Table 4.

Table 4 4- > * average of 3 measurements The increasing concentrations of monomeric AB-RU increase the signal of the standard a as well as that of the standard e. The quotient b / a remains almost constant, an improvement of the resolving power in the lower range (b-a) is not achieved and the dynamics of the measurement range are not improved (e / a almost constant). This is achieved only when oligomeric AB-RU is added. Similar results are obtained for other batches or portions of microparticles. The accuracy and acuracy of the measurement is improved by the use of oligomeric AB which can also be observed in comparisons of the method.

Example 8 Detection of HCG with an oligomeric antibody with / without addition of unlabeled or unlabeled antibody (F (ab ') g) R1: 3.0"ug / ml MAB < HCG > - ruthenium (II) tris- (bipyridyl) - NHS-oligo as F (ab ') 2f degree of polymerization 5-7, degree of ruthenilation 3.3, are dissolved and mixed in a buffer or phosphate buffer of 40 mmole / 1, pH = 7.5 which additionally contains 0.1% bovine IgG and 3% bovine serum albumin (BSA).

R2: 5.0 - / u-g / ml MAB < HCG > -IgG-biotinylated with a degree of biotinylation of 1:10 are used in a reagent as described above in place of MAB-PBRU.

R3: 4 > ug / p? l from PAB < HCG > IgG polyclonal unlabelled or unlabelled, are additionally added to a reagent R1 and mixed.

A series of HCG standards with concentrations of 0 to 20,000 mlU / ml are analyzed in the experimental system as described in example 7 without (R1, R2, beads) and with the addition (R1, R2, beads) of the unlabeled or unlabeled monoclonal antibody. It turns out that a calibration curve of the smoother is obtained when the reactants R2 and R3 are used than when R1 and R2 are used. However, the measurement range is greater in the R2 system, R3 (addition of unlabeled or unlabeled antibody).

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property

Claims (19)

1. A method for the immunological determination of an analyte in a sample liquid according to the principle of an interposition or intercalation test in which the sample liquid is incubated in the presence of a solid phase with at least two receptors capable of binding or bind to the analyte to be determined in which the first receptor is soluble and the second receptor (a) binds to a solid phase or (b) is capable of binding or binding to a solid phase and the analyte is detected by determining the label or label in the solid phase and / or in the liquid phase, characterized in that the first receptor is an oligomer of a binding molecule selected from antibodies, antibody fragments and mixtures thereof.

2. The method according to claim 1, characterized in that the degree of oligomerization of the first receptor is from 2 to 15.

3 . The method according to claim 1 or 2, characterized in that the first receiver includes or carries from 1 to 20 marking or labeling groups.

4. The method according to claim 3, characterized in that the first receiver includes or carries 2 to 10 marking or labeling group.

5. The method according to claim 3 or 4, characterized in that the labeling or labeling group is a group of labeling or labeling of luminescent metal chelate.

6. The method according to claim 5, characterized in that the luminescent metal or metal chelate is selected from the group comprising ruthenium, rhenium, iridium and osmium chelates.

7. The method according to claim 6, characterized in that the luminescent metal chelate is selected from ruthenium chelates.

8. The method according to any of the previous claims, characterized in that the solid phase is composed of a magnetic, particulate material and coated with the second receptor or a material which is capable of binding or binding to the second receptor.

9. The method according to any one of the preceding claims, characterized in that the second receptor carries or includes biotin groups and the solid phase carries or includes avidin or streptavidin groups.

10. The method according to any of the previous claims, characterized in that the determination is carried out in the presence of a labeled or labeled first receptor and additionally of a specific receptor of the unlabeled or non-labeled analyte.

11. An oligomeric antibody comprising a conjugate of at least two antibodies, fragments of antibodies and / or mixtures thereof, characterized in that the degree of oligomerization is 2-15.

12. The oligomeric antibody according to claim 11, characterized in that it itself carries or includes at least one marking or labeling group.

13. The oligomeric antibody according to claim 12, characterized in that the labeling or tagging groups are luminescent metal chelate labeling or labeling groups.

14. The oligomeric antibody according to claim 13, characterized in that the luminescent metal chelate is selected from ruthenium chelates.

15. The oligomeric antibody according to any of claims 12-14, characterized in that the number of labeling or labeling groups is from 2 to 20.

16. A process for the production of an oligomeric antibody according to one of claims 11-15, characterized in that the antibodies and / or fragments thereof are linked or covalently linked together.

17. The use of an oligomeric antibody according to one of claims 11-15 as a detection reagent in an interposition or intercalation assay.

18. The use of an oligomeric antibody according to one of claims 11-15 for the reduction and / or prevention of the Hook effect (hook effect) in an immunological method.

19. The set of reagents for the immunological determination of an antigen, characterized in that it comprises an oligomeric antibody according to one of claims 11-15 and an antibody which binds to a solid phase or which is capable of binding or binding to a solid phase.