Hybridoma Secreting Monoclonal Antibody Research Articles

Production of monoclonal antibody against a major purgative component, sennoside A, its characterization and ELISA

For immunization, sennoside A was conjugated with bovine serum albumin. The hapten number in an antigen conjugate was determined to be five by matrix-assisted laser desorption/ionization TOF mass spectrometry. A hybridoma secreting monoclonal antibody against sennoside A was produced by fusing splenocytes immunized with sennoside A–bovine serum albumin and a hypoxantine–aminopterin–thymidine (HAT)-sensitive mouse myeloma cell line, P3-X63-Ag8-653. Weak cross-reactivities occurred with sennoside B which is a stereochemical isomer, and a monomer of sennoside A, rhein, but no cross-reactivities were observed with other related anthraquinones and phenolics. The full range of the assay extends from 20 to 200 ng ml−1 of sennoside A. Good correlation of sennoside A concentrations in crude extract of rhubarb between ELISA and HPLC methods was obtained. The contents of sennoside A in various rhubarb roots were assayed by the newly established ELISA indicating a good agreement with the previous reports.

植物二次代謝産物に関わる生薬学的研究

Clonal micropropagation on various medicinal plants was set up resulting in the regenerated plants which possessed a homogeneous quality. The ratio of hapten to bovine serum albumin (BSA) in an antigen conjugate was determined by matrix-assisted laser desorption/ionization of mass spectrometry. A hybridoma secreting monoclonal antibody (MAb) was produced by fusing splenocytes immunized with an antigene-BSA conjugate with mouse myeloma cells. Competitive enzyme-linked immunosorbent assay (ELISA) using MAb was set up as a high sensitive, specific and reproducible qualitative method. A method of determination for ginsenosides by using a unique western blotting was established. Immunoaffinity column chromatography using an anti-ginsenoside Rb1MAb has made possible a single-step separation of ginsenoside Rb1 from a crude ginseng extract. Single chain Fv gene of anti-forskolin MAb was prepared from mRNA of hybridoma secreting anti-forskolin MAb and cloned. Gene was constructed into a pET-28a(+) vector producing a scFv protein. Modeling of forskolin and scFV was investigated. THCA synthase was purified from the homogenate of Cannabis sativa leaves on successive column chromatographies. THCA synthase was confirmed to be homogeneity having 75 kDa. To obtain the corresponding cDNA clone of THCA synthase, a set of degenerate promers was constructed based on N-terinal and internal amino acid sequences of THCA synthase. The 5' and 3' ends of cDNA were amplified by RACE. A full sequencing has been determined to be corded a polypeptide having 545 amino acid residues. The cDNA clone was expressed in yeast system via PUC19 vector resulting in THCA synthase activity.

Monoclonal antibodies against naturally occurring bioactive compounds.

The ratio of hapten to bovine serum albumin (BSA) in an antigen conjugate was determined by matrix-assisted laser desorption/ionization (MALDI) tof mass spectrometry. A hybridoma secreting monoclonal antibody (MAb) was produced by fusing splenocytes immunized with an antigen-BSA conjugate with HAT-sensitive mouse myeloma cells. The cross-reaction of anti-forskolin antibodies with 7-deacetyl forskolin was 5.6%. A very small cross-reaction appeared with other derivatives. The full measuring range of the assay extends from 5 ng to 5 mug/ml of forskolin. Immunoaffinity column chromatography using anti-forskolin MAbs appears to be far superior to previously published separation methods. The capacity of the immunoaffinity column as determined by ELISA is 9 mug/ml. Forskolin has been isolated directly from the crude extracts of tuberous roots and the callus culture of Coleus forskohlii. A MAb against tetrahydrocannabinolic acid (THCA) was produced. The cross-reaction of anti-THCA antibody against other cannabinoids was very wide. Many cannabinoids and a spiro-compound were reactive, but did not react with other phenolics. It became evident that this ELISA was able to be applied to the biotransformation experiments of cannabinoids in plant tissue culture system. Anti-ginsenoside Rb1 MAbs were produced. New western blotting method of determination for ginsenosides was established. Ginsenosides separated by silica gel TLC were transferred to a polyvinylidene difluoride (PVDF) membrane. The membrane was treated with NaIO(4) solution followed by BSA, resulting in a ginsenoside-BSA conjugate. Immunostaining of ginsenosides was more sensitive compared to other staining. Immunostaining of ginsenosides in the fresh ginseng root was succeeded using anti-ginsenoside Rb1 (GRb1) MAb after blotting to PVDF membrane.

Formation of monoclonal antibody against a major ginseng component, ginsenoside Rb1 and its characterization.

The ratio of hapten and bovine serum albumin in an antigen conjugate was determined by matrix-assisted laser desorption/ionization mass spectrometry. A hybridoma secreting monoclonal antibody against ginsenoside Rb1 was produced by fusing splenocytes immunized with a ginsenoside Rb1- bovine serum albumin conjugate with HAT-sensitive mouse myeloma cell line, P3-X63-Ag8-653. A very small cross-reaction appeared with ginsenoside Rc and ginsenoside Rd. The full measuring range of the assay extends from 20 ngml-1 to 400 ngml-1 of ginsenoside Rb1.

Development of ELISA-analysis methods for the quantification of bioactive natural products in plants, phytomedicines and in humans or similar

In the course of a program in developing new ELISA-methods for the quantification of bioactive natural products in plants, phytomedicines and animals in a μg and ng scale, monoclonal antibodies against various natural products of medicinal and analytical importance have been developed. The ratio of hapten to bovine serum albumin (BSA) in an antigen conjugate was determined by matrix-assisted laser desorption/ionization (MALDI) of mass spectrometry. A hybridoma secreting monoclonal antibodies (MAb) was produced by fusing splenocytes immunized with an antigen-BSA conjugate with HAT-sensitive mouse myeloma cells. The cross-reaction of anti-forskolin antibodies with 7-deacetyl-forskolin was 5.6%. A very small cross-reaction appeared with other derivatives. The full measuring range of the assay extends from 5 ng to 5 μg/ml of forskolin. Immunoaffinity column chromatography using anti-forskolin MAbs appears to be far superior to previously published separation methods. The capacity of the immunoaffinity column as determined by ELISA is 9 μg/ml. Forskolin has been isolated directly from the crude extracts of tuberous roots and the callus culture of Coleus forskohlii. A MAb against Δ(1)-tetrahydrocannabinolic acid (THCA) was produced. The cross-reaction of anti-Δ(1)-THCA antibody against other cannabinoids was very wide. Many cannabinoids and a spiro-compound were reactive, but did not react with other phenolics. It became evident that this ELISA method was able to be applied to the biotransformation experiments of cannabinoids in plant tissue culture system. Anti-solamargine MAbs were produced. A method of determination for solasodine glycosides by using TLC-immunostaining was established. Solasodine glycosides separated by silica gel TLC were transferred to a polyvinylidene difluoride (PVDF) membrane. The membrane was treated with NaIO(4) solution followed by BSA, resulting in a solasodine glycoside-BSA conjugate. Immunostaining of solasodine glycosides was more sensitive compared to other staining. Immunostaining of ginsenosides in fresh ginseng root was successful using anti-ginsenoside Rb1 (G-Rb1) MAb after blotting to PVDF membrane.

Production of monoclonal antibodies and development of an ELISA for solamargine

The ratio of hapten and bovine serum albumin in an antigen conjugate was determined by matrix-assisted laser desorption/ionization mass spectrometry. A hybridoma secreting monoclonal antibodies against solamargine was produced by fusing splenocytes immunized with a solamargine-bovine serum albumin conjugate with HAT-sensitive mouse myeloma cell line, P3-X63-Ag8-653. Extensive cross-reaction of anti-solamargine antibodies against solasonine appeared. Aglycone of solamargine, solasodine cross-reacted with anti-solamargine antibodies resulting in a 43.8% cross-reaction. Insignificant cross-reaction appeared with tomatine (2.06%). The full measuring range of the assay extends from 57.5 pmol ml(-1) to 11.5 nmol ml(-1) of solamargine.

Anti-CD40 monoclonal antibody induces the proliferation of murine B cells as a B-cell mitogen through a distinct pathway from receptors for antigens or lipopolysaccharide

To study the activation and differentiation of murine B cells, we prepared a hybridoma secreting monoclonal antibody, LB429, which can directly induce the proliferation of murine B cells in vitro. LB429 recognizes a B cell-specific surface molecule of 45 kDa. It recognizes an epitope of murine CD40 produced as a soluble fusion protein with glutathione S-transferase. LB429 stains COS-7 transfectant with murine CD40 cDNA and mature B-cell lines but does not stain pre-B cell lines. Two-color staining demonstrated that the epitope recognized with LB429 appears on the surface of B220 + cells of spleen and bone marrow. LB429 can induce a strong proliferation of murine B cells from spleen in the absence of initial triggering with anti-IgM antibody or with anti-IgM antibody + IL-4. LB429 induced the cell size enlargement and the cell cycle transition of resting B cells as well as lipopolysaccharide (LPS). LB429 and LPS stimulate B cells synergistically in vitro by accumulating 44.7% of cells in S/G2/M phases of cell cycle. However, stimulation of spleen B cells with LB429 resulted in the increase of sIgM high + sIgD high + B cells, in contrast LPS showed the proliferation of both sIgM high + sIgD high + B cells and sIgM low + sIgD high + B cells. These results suggested that LB429 and LPS cause the proliferation of B cells through different stimulatory pathways. This anti-mouse CD40 antibody (LB429) is a very useful reagent to study the activation and differentiation of B cells in vitro.

Nucleotide sequence of the variable region of the heavy and light chains of a monoclonal IgG antibody reactive to herbicides, terbutryn and prometryn.

Members of the triazine family of herbicides are reliable indicators of contamination of the ground water or soil with pesticide residues. To facilitate better detection of the chemical residues using improved immunoassay procedures, several monoclonal antibodies against triazine herbicides have been developed. K1F4 is a hybridoma secreting monoclonal (IgG) antibody reactive to terbutryn and prometryn, two members of the triazine family. We have cloned the genes encoding the variable regions of the heavy and light chains of this monoclonal antibody and report the nucleotide sequence here.

Production of monoclonal antibodies and enzyme immunoassay for typical adenylate cyclase activator, Forskolin.

The ratio of hapten to bovine serum albumin in an antigen conjugate was exactly determined by matrix-assisted laser desorption/ionization mass spectrometry. A hybridoma secreting monoclonal antibodies against forskolin was produced by fusing splenocytes immunized with a forskolin-bovine serum albumin conjugate with HAT-sensitive mouse myeloma cells. The cross-reaction of anti-forskolin antibodies with 7-deacetyl forskolin was 5.57%. A very small cross-reaction appeared with 1-deoxy, 9-deoxy and 1,9-dideoxy forskolin derivatives. The full measuring range of the assay extends from 6 ng to 200 ng of forskolin. The competitive ELISA assay used for this analysis was found to be more sensitive than TLC (10 micrograms), GLC (30 ng) and HPLC (1 microgram) methods.

Rapid generation of monoclonal antibody-secreting hybridomas against African horse sickness virus by in vitro immunization and the fusion/cloning technique

Splenocytes from non-immune mice were stimulated in vitro using an equimolar mixture of factors from mixed lymphocyte reaction (MLR) and from phorbol-12-myristate 13-acetate (PMA) stimulated EL-4 cells, and concomitantly immunized with inactivated African horse sickness virus (AHSV) antigen serotype 4 or viral proteins 2 and 5 from AHSV serotype 9. Fusion with NSO myeloma cells was performed five days after primary or secondary stimulation/immunization. The record of hybridoma growth after a standard method of fusion, expansion of cells and subsequent cloning was compared with a fusion/cloning method in which cells were cloned within 2 to 3 days of the fusion event. Detection of antigen specific antibodies in the hybridoma culture supernatants was successful only with cells derived from primary stimulation/immunizations. Antibodies were detected using an indirect ELISA with the immunizing antigen coated on to the surface of the plates. Monoclonal hybridomas were isolated within 2 to 3 weeks using the fusion/cloning method, compared with the standard method, where it took 4 to 5 weeks. Although the total number of clones isolated from the fusion/cloning method was less than that obtained through the standard method, the yield of specific antibody-producing hybridomas as a percentage of the total picked was often more efficient with the fusion/cloning method. With respect to the immunoglobulin isotype produced, not all of the antibodies could be classified by the ELISA system used; 14% of anti-AHSV positive clones were identified as IgG-secreting cells, 25% as IgM-secreting, 18% were cross-reacting with IgG and IgM, and 43% could not be classified. Similar results in all aspects of the work were obtained whether a crude infected cell extract or purified outer capsid polypeptides VP2/5, from serotype 4 and serotype 9 respectively, were used.

Immunopurified 25-hydroxyvitamin D 1 alpha-hydroxylase and 1,25-dihydroxyvitamin D 24-hydroxylase are closely related but distinct enzymes.

The chick kidney mitochondrial cytochrome P-450 1,25-dihydroxyvitamin D3 24-hydroxylase was partially purified by sequential polyethylene glycol precipitation, aminohexyl-Sepharose 4B, and hydroxylapatite chromatography. The specific activity of the final preparation, when reconstituted with NADPH, adrenodoxin, and adrenodoxin reductase, was 245 pmol/min/mg of protein or 0.56 pmol/min/pmol of P-450. The specific cytochrome P-450 content was 0.45-0.73 nmol/mg of protein. BALB/c mice immunized with this preparation developed serum polyclonal antibodies to the 24-hydroxylase, as demonstrated by immunoprecipitation. Splenic lymphocytes from an immunized mouse were fused with myeloma NSI/1-Ag-4-1 cells, and hybridomas secreting monoclonal antibodies to the 24-hydroxylase were detected by immunoprecipitation. The hybridoma lines were cloned by limiting dilution and further characterized as IgG1, IgG3, and IgM subclasses. In one-dimensional immunoblots of soluble 24-hydroxylase preparations, the monoclonal antibodies revealed a single band with an apparent molecular weight of 59,000. The monoclonal antibodies did not cross-react with cytochrome P-450s from other species but immunoprecipitated and immunoblotted a soluble chick renal mitochondrial 25-hydroxyvitamin D3 1 alpha-hydroxylase preparation, demonstrating the close similarity of these two hydroxylases. These antibodies were coupled to Sepharose CL-4B and used to isolate to homogeneity the two enzymes from chick kidney mitochondria. Amino-terminal sequences and amino acid composition data demonstrate that these enzymes are different but homologous.

Production and characterization of monoclonal antibodies against non-A 1c glycated hemoglobin

Hybridomas secreting monoclonal antibodies specific for hemoglobin nonenzymatically glycated in the non-A 1c position were produced by fusion of SP 2/0 myeloma cells with spleen cells from BALB/c mice immunized with nonenzymatically glycated hemoglobin prepared from human erythrocytes. Wells containing hydridomas secreting antibodies against glycohemoglobin were identified by binding, in an enzyme-linked immunosorbent assay, to purified glycated hemoglobin. The colony designated E85, which secreted antibodies discriminating between glycated versus unglycated hemoglobin, was cloned at least four times by limiting dilution and used for further study, performed with purified monoclonal antibody. Specificity of E85 was demonstrated by immunoblotting and by ELISA, wherein the monoclonal antibody reacted with glycated hemoglobin but not with hemoglobin A 1c or with unglycated hemoglobin. Immunoblotting of human plasma with E85 on nitrocellulose yielded no reactive proteins, indicating site specificity for glycated epitopes residing in hemoglobin but not in other nonenzymatically glycated proteins present in plasma. E85 differs from other antibodies raised against glycated hemoglobin and other glycated proteins, which recognize hemoglobin glycated at the N terminal valine of the β chain (HbA 1c) or which recognize glycated residues only after reductive conversion to glucitollysine and which do not discriminate between different glycated proteins. Thus, this report describes the establishment of the first hybridoma secreting monoclonal antibody raised against a physiologic (unreduced) form of non-A 1c glycohemoglobin, and for the glycated epitope when it resides in glycohemoglobin but not in other proteins or in hemoglobin A 1c.

Cartilage proteoglycan‐induced arthritis in BALB/c mice. Antibodies that recognize human and mouse cartilage proteoglycan and can cause depletion of cartilage proteoglycan with little or no synovitis

Human fetal cartilage proteoglycan (PG) induces the development of an erosive polyarthritis and spondylitis in BALB/c mice. We have examined the properties of 3 monoclonal antibodies (MAb) to human fetal cartilage PG isolated from immunized mice that cross-react with mouse cartilage PG. Compared with sera from arthritic mice, which contain antibodies reactive with keratan sulfate, MAb 202 (IgG1) reacted only with a protein-related epitope that is distributed on both hyaluronic acid-binding and chondroitin sulfate-attachment regions. MAb 813 (IgG1) reacted with the same fragments and recognized an epitope with the immunologic characteristics of keratan sulfate. MAb 945 (IgM) remains to be further characterized. Introduction of hybridomas secreting MAb 202 and MAb 945 into irradiated mice resulted in the loss of PG from articular cartilage and from growth plate cartilage (with MAb 202 only), as revealed by a loss of staining with toluidine blue. There was no synovial hyperplasia with MAb 202, but some hyperplasia and mononuclear cell infiltration was seen with MAb 945. This was accompanied by the binding of immunoglobulins to articular cartilage, as demonstrated by immunofluorescence. The hybridoma secreting MAb 813 produced no cartilage changes or synovitis, and there was no immunoglobulin binding to cartilage. Polymorphonuclear leukocyte infiltration was never observed with these antibodies. These studies indicate that MAb reactive with mouse cartilage PG can cause the depletion of PG from hyaline cartilage by mechanisms that may be both complement dependent and complement independent. Antibodies may serve to release and expose PG antigen to immune cells, as well as causing a loss of the mechanical properties of cartilage that are PG dependent.

Use of Anti-Cholera Toxin Iga-Secreting Hybridoma Cells for the Elaboration of an Antigen-Specific Iga-Elispot-Assay

Hybridoma anti-cholera toxin (CT) IgA-secreting cells, because of their monoclonal character, were used to establish and optimize an ELISPOT-assay for CT-specific IgA-secreting cells. The use of hybridoma cells easily and quickly allowed the elaboration of a sensitive, specific and reproducible ELISPOT-assay, which was successfully applied to enumerate intestinal lamina propria lymphoid cells secreting anti-CT IgA in mice immunized twice intraintestinally with CT. Monoclonal antibody-secreting hybridoma cells, if available against a given antigen, are suggested as ideal cell suspensions to elaborate new ELISPOT-assays to study antibody responses at the cellular level.

Production of an equine monoclonal antibody specific for the H7 hemagglutinin of equine influenza virus

Peripheral blood leucocytes from a pony previously exposed to equine influenza virus (H3, N8) and vaccinated with killed virus (H3, N8 and H7, N7 subtypes) were cultured in vitro with live A/equine/Prague/56 (H7, N7). On the sixth day of culture, cells were harvested and fused with mouse myeloma cells (X63-Ag8.653). From this fusion, one hemagglutinin specific, equine IgG monoclonal antibody secreting hybridoma was identified and cloned twice by limiting dilution. The antibody inhibited hemagglutination by nine H7 equine influenza virus isolates obtained over a 21-year period, but did not inhibit A/equine/Miami/63 (H3, N8), or A/PR/8/34 (H1, N1). The neutralizing titer of hybridoma induced, nude mouse ascitic fluid was 10 −4.5 when tested in eggs against 100 egg infective doses (EID 50) A/equine/Prague/1/56. The hybridoma continued to synthesize antibody during more than 4 months in continuous culture.

High level expression of p55, a thyroid hormone binding protein which is homologous to protein disulfide isomerase in a retroviral vector

To develop an efficient system for a high level expression of a human cellular thyroid hormone binding protein (p55) in eukaryotic cells, a full-length p55 cDNA was inserted into a Harvey murine sarcoma virus-derived vector (pHTBr) and transfected into mouse NIH 3T3 cells. The expressed p55 has a molecular weight of 55,000 and is recognized by the human specific anti-p55 monoclonal antibody. Similar to the endogenous p55, the expressed p55 is localized on endoplasmic reticulum and nuclear envelope. Moreover, p55 was specifically labeled by N-bromoacetyl-3,3′,5-triiodo-L-thyronine. Thus, the expressed p55 is structurally indistinguishable from the endogeneous p55. pHTBr was packaged into a virus with the aide of an amphotropic virus. Infection by pHTBr-containing virus yielded a 2–11 fold higher expression than the endogeneous p55 in NIH3T3, rat GH 3, human HepG2 cells and a mouse monoclonal antibody secreting hybridoma.

A Live Cell Enzyme-Linked Immunosorbent Assay for Detecting Human Hepatoma Membrane Antigens

Live cell enzyme-linked immunosorbent (ELISA) and fixed cell indirect immunofluorescence (IF) assays were compared to screen mouse hybridomas producing immunoreactive monoclonal antibodies against cell membrane antigens expressed on Ha22T, a human hepatoma cell line. While performing live cell ELISA, two parameters were tested to improve the viability of the target cells. The first parameter was the inclusion of growth medium in the assay buffers, and the second was performing the assay incubations at 37 degrees C in an incubator containing 5% CO2 in the air. Fixed cell IF detected and classified 46% of the hybridomas secreting monoclonal antibodies reactive with membrane, cytoplasm, cytoskeleton, and nuclear antigens of Ha22T cells. Fixed cell IF was able to reveal mixtures of two or more hybridomas growing in the same well secreting antibodies to different cell organelles. The live cell ELISA, on the other hand, identified 12 additional membrane reactive monoclonal antibodies from the hybridoma supernatants that were not reactive by IF. These results disclose that cell fixation procedures used for IF either completely or partially inactivated some of the cell membrane antigens. We, therefore, propose the use of a combination of immunoassays to select the maximum number of hybridomas secreting useful monoclonal antibodies from somatic cell fusions.

The T cell receptor Vβ6 domain imparts reactivity to the Mls-1 a antigen

A monoclonal antibody secreting hybridoma was established by fusing spleen cells from a rat immunized with a murine T cell clone, OI11, which has I-Ab restricted specificity for the male H-Y antigen and unrestricted specificity for the minor lymphocyte stimulating antigen, Mls-1 a, to the mouse myeloma P3X63AG8.653 and screening for the capacity of the hybridoma supernatants to stimulate the OI11 T cell clone. An antibody (RR4–7) was found to be specific not only for the immunizing T cell clone but virtually for all T cells using the Vβ6 TCR gene product as part of their surface antigen receptor. When the expression of the Vβ6 gene in various strains of mice was analyzed, it was found that strains expressing the Mls-1 a antigen contained few T cells expressing Vβ6-encoded TCRs. The majority of T cell hybridomas which expressed Vβ6-encoded TCRs were found to be reactive to the Mls-1 a antigen. These data confirm the finding of H. R. MacDonald et al. (Nature (London) 332, 40, 1988) that most TCRs encoded by the Vβ6 gene have a biased specificity for the Mls-1 a antigen.

A simple hemagglutination method for the detection of cell surface antigens

A rapid, easy and reproducible hemagglutination method is described for the detection of cell surface antigens. This method can be used for the determination of cell subpopulations and the screening of monoclonal antibody-secreting hybridomas. Fresh or paraformaldehyde-fixed cells, which have previously been labeled with an appropriate monoclonal antibody (of known or unknown specificity), are reacted with human erythrocytes coupled with the second antibody (rabbit anti-mouse immunoglobulins), in a round bottomed 96-well microtiter plate. The presence of specific agglutination and the end-point of serial dilutions of the labeled cells with unlabeled ones give an approximate estimation of the percentage of cells reacting with the monoclonal antibody under examination. The hemagglutination results correlate well with the results obtained using a conventional immunofluorescence method.

Production and characterization of monoclonal antibodies against human glycoalbumin

Hybridomas secreting monoclonal antibodies specific for nonenzymatically glycated albumin were produced by fusion of SP2 0 myeloma cells with spleen cells from BALB/c mice immunized with unreduced nonenzymatically glycated albumin prepared from human plasma. Wells containing hybridomas secreting antibodies against glycoalbumin were identified by binding, in an enzyme-linked immunosorbent assay, to glycoalbumin isolated from human plasma or to albumin that had been glycated in vitro. The colony designated A717, which secreted antibodies discriminating between glycated versus unglycated albumin, was cloned four times by limiting dilution and used for further study, performed with monoclonal antibody purified from mouse ascites fluid. Specificity of A717 was demonstrated by immunoblotting and by ELISA, wherein the monoclonal antibody reacted preferentially with glycated albumin but insignificantly with unglycated albumin. Immunoblotting of human plasma with A717 on nitrocellulose yielded a single band, the electrophoretic mobility of which corresponded with that of authentic glycated albumin, indicating site specificity for glycated epitopes residing in albumin but not in other nonenzymatically glycated serum proteins. A717 differs from other antibodies raised against glycated albumin and other proteins, which recognize glycated residues only after reductive conversion to glucitollysine and which do not discriminate between different glycated proteins. Thus, this report describes the establishment of the first hybridoma secreting monoclonal antibody raised against unreduced glycated albumin, which is the physiologic form occuring in vivo, and for the epitope when it resides in albumin but not other proteins.