METHOD FOR AFFINITY PURIFICATION OF HYBRIDOMA ANTIBODIES

Abstract: A efficient process design for purifying large quantities of specific antibodies by affinity chromatography. By utilizing the process strategy described, large scale production of highly purified hybridoma antibodies and other proteins becomes feasible. The initiation of the process centers on production of hybridoma proteins which bind to a commonly available inexpensive protein such as human serum albumin (HSA) with which large quantities of a protein such as mouse immunoglobulin can be isolated by affinity chromatography. The mouse immunoglobulin is covalently linked to an inert matrix, such as Sephrose beads and this affinity reagent is used to purifiy a large quantity of a hydridoma protein such as rat anti-mouse IgG antibody. This rat anti-mouse IgG antibody can then be linked to sepharose beads and can be used as a general affinity reagent for the purification of any mouse immunoglobulin.

Description: METHOD FOR AFFINITY PURIFICATION OF HYBRIDOMA " ANTIBODIES Cross Reference to a Related Application Thiβ application is a continuation~in-part of U.S. application Serial No. 228,548 entitled " Growth Medium and Process for Producing Monoclonal Antibodies", filed January 26, 1981, the teachings of which are incorporated herein by reference. Background of the Invention This invention relates generally to the production of hybridoma proteins and more specifically to the production of hybridoma antibodies. It has been postulated that if one could isolate one cell making a single specific antibody and grow it in culture, the cell's progeny or clone would be a source of large .amounts of identical antibody against a single antigenic deterrainant-a monoclonal antibody. Unfortunately, antibody-secreting cells cannot be maintained in a culture medium. There are malignant tumors of the immune system called myelomas, however, whose rapidly proliferating cells can produce large amounts of abnormal immunoglobulins called myeloma proteins in a culture medium. In more basic terms, a myeloma is an old tumor which is no longer capable of producing antibodies (a plasrαocytoma) . In 1975, investigators learned how to fuse mouse myeloma cells with lymphocytes from the spleen of mice immunized with a particular antigen. The resulting hybrid-myeloma, or "hybridoma", cells express both the lymphocyte's property of specific-antibody production and the immortal character of the myeloma cells. By following the fusing or splicing technique discussed above which is described in articles entitled "Antibody Reagents Revolutionizing Immunology" by Jeffrey L. Fox, January 1, 1979, C&EN, and "Monoclonal Antibodies" by Yelton and Scharff, American Scientist, Vol. 168, pp. 510-516, cells that secrete antibodies can be made immortal by fusing them with tumor cells and cloning the hybrids. Each clone is a long-term source of substantial quantities of a single highly specific antibody. Highly specific monoclonal antibodies produced by this general method have proved to be a remarkably versatile tool in many areas of biological research and clinical medicine. It is these hybridomas which produce antibodies or "hybridoma antibodies" as they can be called toward which the present invention is directed. Once an antibody producing clone is produced from a hybridoma cloned cells can be utilized to produce antibodies in two ways. One method is to inject the cloned cells into the belly of a mouse. While in the belly of the mouse, the antibody producing clone proliferates and the antibody it makes becomes concentrated by the mouse in the fluid of the belly (ascitic fluid) and in the blood. The antibody is harvested by tapping the fluid from the belly atraumatically with a needle and syringe. A major disadvantage, however, of raising the hybridoma antibody in vivo is that in the process, the hybridoma product becomes mixed with all of the other immunoglobulins present in the mouse and is no longer monoclonal. Of course the alternative to any jn vivo procedure like the one discussed above is an in vitro procedure. The problem with producing antibodies from hybridomas in culture, however, results from the fact that the hybridoma releases the antibody in the culture medium to produce a very dilute antibody containing liquid. Indeed the amount of antibody in a tissue culture supernatant is typically in the order of about 10 micrograms per milliliter. As can be appreciated, , recovery of an antibody from such dilute supernatant greatly increases recovery costs. However, an iτ_ vitro procedure has at least one distinct advantage over an _in vivo procedure. The marked advantage of the __ vitro procedure is that the culture conditions can be easily arranged so that the species of immunoglobulin being produced in the culture (the hybridoma product) is different from that of any other which may be contaminating the culture medium. For example, bovine serum normally has to be added to the culture system and thus bovine immunoglobulins will be mixed with the hybridoma product (normally mouse or rat) . The important point is that in an jLn vitro production method, conditions can be easily adjusted so that the hybridoma product being grown is unique with regard to its derivative species and that is not the case with the fluid recovered from the belly of an animal. The major problem to be dealt with, in raising hybridoma antibodies or other proteins _in_ vitro is to devise a method of purifying and concentrating the desired monoclonal antibody without co-purifying the chemically similar immunoglobulins derived from the serum supplement to the tissue culture medium. Of course it would be highly desirable to have a reagent which is specific for the protein to be recovered (mouse immunoglobulin for example) . In short, hybridoma antibodies and other proteins produced in tissue culture occur at very low concentration and thus are difficult to purify in good yield at reasonable cost. On the other hand, proteins such as antibodies produced _irι vivo are contained in a fluid with other proteins which present purification problems. Both problems would be reduced if one had available large quantities of a reagent that binds mouse immunoglobulins or other proteins specifically. Summary of the Invention In accordance with the present invention, one hybridoma antibody is produced and collected against an inexpensive protein such as human serum albumin. Human serum albumin is relatively inexpensive and is used to initiate a process which produces a reagent for collecting the protein to be recovered. With a column loaded with such a reagent, a means exist for the continued recovery of antibodies and other proteins from dilute solutions. Accordingly one important object of the invention is to provide a method for the economical recovery of proteins including antibodies from dilute solutions. Brief Description of the- Drawing The sole figure of the drawing is a flow sheet of the process in accordance with the present invention. "BUREAU OΛ.PI Description of the Preferred Embodiments At the outset the invention is described in its broadest overall aspects with a more detailed description following. In its broadest overall aspects the protocol of the present method employs one hybridoma protein, for example a rat anti-mouse immunoglobulin hybridoma antibody, to bind the protein to be recovered, for example a mouse antibody. As is readily apparent to those skilled in this art, anti-mouse immunoglobulin is an antibody that reacts with mouse immunoglobulin or antibody. A rat is selected to produce the anti-mouse immunoglobulin because of the good fusion efficiency that is obtained by fusing the spleen cells from a rat with the mouse myeloma. Of course any animal could be utilized which enables the production of hybridoma producing proteins specific to the protein to be recovered. An important aspect of the present process is to make a large amount of the protein such as the rat antimouse IgG whfch is specific to the product to be recovered. However, in order to make such an affinity reagent, a source of mouse IgG (or other specific protein) is needed so that sufficient quantities of rat antimouse IgG may be easily purified. Unfortunately large amounts of mouse IgG can't be made from a mouse because a mouse has too little to begin with. However, it is possible to make another hybridoma which produces protein specific against a protein or antigen which is easily available in large quantities. Such an antigen is human serum albumin (HSA) . Thus in accordance with the present. invention, the preferred inexpensive starting material is HSA. The HSA is immobilized on an affinity matrix such as Sepharase beads (product of Pharmacia) . A next step, for example, is to make a mouse anti-HSA hybridoma (to be used as the source of mouse IgG) and purify the antibody produced on an HSA affinity column. Such a column will collect a large quantity of mouse IgG. The mouse IgG is then separated from the HSA column and used to prepare a mouse IgG column. The mouse IgG is then linked to an affinity chromotography column to produce a mouse IgG column. The next step in the procedure is to produce a rat anti-mouse hybridoma. Next the rat anti-mouse antibody is collected on the mouse IgG * column. The rat anti-mouse immunoglobulin is then separated by acid elution and used to make a rat anti-mouse immunoglobulin column which is a general reagent for the extraction and purification of mouse antibody from culture supernatant. It should be noted that the mouse IgG directed against the commonly available antigen, HSA, is needed only to initiate this general purification scheme. For example, once one obtains one gram of mouse anti- HSA, when linked to the Sepharose matrix, that one gram can be used to make two grams of rat anti-mouse IgG antibody. This, in turn can be used to purify four grams of mouse IgG directed against any antigen. This additional mouse IgG, when linked to the sepharose matrix, can in turn be used to make eight grams of rat "BUREΛ^ 0M anti-mouse IgG. Thus, this system can be both self perpetuating as well as providing, a purification method for obtaining any protein (hybridoma or otherwise) in pure form. It should be noted that this same method can be used to make large quantities of any affinity reagent such as mouse anti rat IgG or mouse anti human IgG. It should also be noted that, in general this same method can be applied to hybridoma products raised in the ascitic fluid form but in that case the purified products obtained are no longer strictly monoclonal. The invention is further illustrated by the following nonlimiting example in which: Balb/C is a particular inbred strain of mouse CFA is complete Freund s adjuvant IFA is incomplete Freund's adjuvant SC is subcutaneously IV is intravenous PEG is polyethylene glycol 1000 BSA is bovine serum albumin RT is room temperature (20°C) DMEM is a standard tissue culture medium commercially available from Grand Island Biological Co., Grand Island, N.Y. DMEM A is DMEM supplemented with antibiotics DMEMIOA is DMEM supplemented to 10% with calf serum and antibiotics HAT is DMEM and serum with hypoxanthine, aminopterin, and thymidine. HT is HAT without aminopterin. PBS is phospate buffered saline which is .15M NaCl, .01M phosphate at pH 7.3 Tris is Tris (hydroxymethyl) aminomethane buffer, product of Sigma Chemical Co. DMSO is dimethyl sulfoxide PO is total phosphate ion CS is calf serum c means "with" and o means "without". General Procedures Used: Hybridoma Summary The specific plasmacytoma used for fusion with the spleen cells in this procedure was the non-secreting variant of MOPC 21 which is designated P3-NSI-l-Ag4-l. Balb/C mice or Lewis rats were immunized according to the following schedule. I munize c antigen—in CFA, 20-50 g injected SC in 2 sites (14-30 days) Boost " c 20-50 g in IFA, SC in 2 sites (14-30 days) Inject c 20 g IV 4 days Remove spleen c sterile technique Make single-cell suspension Mix 10:1 (spleen:myeloma) ratio of cells Add 32% PEG for total of 8 minutes, including 3 minute .spin (1200 RPM) Remove PEG, add medium Incubate at 37°C for 24 hours in bacteriological plate The cells are washed, resuspended in selective medium (HAT) , and then plated in 96 well tissue culture plates. The HAT medium is changed about every other day. At about day 10, the medium is changed to HT, the wells are tested for antibody activity, and positive wells are subcloned. In successful lymphocyte-myeloma fusions, spleen cells transfer mechanism to survive in aminopterin. "BU RE ^ Radioimmunoassay Procedure (Used to test for antibody activity) 1. Add in 25 the antigen (40 g/m ) to wells of a 96 well polyvinyl chloride plate. 2. Cover plate c parafilm. Incubate at 37°C for 1-2 hours. Plates can then be refrigerated o removing excess fluid from wells for several days. 3. Aspirate fluid from wells without touching sides of wells. Wash 4-5 times c PBS (containing 1% BSA, 0.02% NaN 3 ). Fill wells and incubate at RT, uncovered for 1/2 hr. 4. Aspirate fluid from wells without touching the plastic. Add 25 of antibody sample to designated wells. Cover c parafilm and incubate 20—24 hours at RT. * 5. Aspirate fluid and wash 4-5 times c PBS (containing 1% BSA, 0.02% NaN 3 ). Add 25 I 125 goat antimouse IgG (or goat antirat Ig if a rat hybridoma is being tested for). Cover c parafilm and incubate in hood, behind lead shield for 20-24 hours at RT. 6. Aspirate fluid and wash 4-5 times c PBS (containing 1% BSA, 0.02% NaN 3 ). Let wells dry. 7. Cut out wells into individual tubes- 8. Count in gamma spectrometer. " B URE Λ TT- Cell Fusion Preparation of Spleen Cell Suspension ( Everything at Room Temp . ) Kill mouse by cervical dislocation. Swab left side of mouse c alcohol (scrub solution). Place mouse on sterile pad. Using sterile instruments (scissors, forceps), cut through skin and pull back. Cut through abdominal wall and remove spleen. Place spleen in sterile petri dish containing sterile PBS. Bring dish to tissue culture hood. Rinse with PBS and remove excess. Add small amount of DMEM A . Tease spleen apart using scalpel and forceps (c teeth). Draw suspension gently up and down syringe several times. Transfer suspension to sterile tube and allow clumps to settle. Transfer suspension without clumps to a second tube containing 10 m DMEM A . Centrifuge cells, 800 rpm 5 minutes. Remove supernatant. Resuspend pellet in 1 m lysing solution (9 parts .83% NH 4 C1, 1 part .17M Tris pH 7.65). Let solution sit 5 minutes. Add 10 m DMEM A and spin again. Resuspend pellet in 15 m DMEM . Count spleen cells in heraocytometer. Cell Fusion Day 0 Melt stock PEG at 37°C. Dilute an aliquot PEG to 32% c DMEM A . Count MOPC tumor cells (it may be necessary to spin down if volume is too large). To a round-bottomed Falcon tube, add a ratio of 4:1-10:1 (spleen to MOPC) cells. Spin cell mixture down at 800 rpm for 5 minutes. Suction off supernatant. Resuspend pellet by tapping tube sharply. Add 0.5 32% PEG to pellet, shake very gently (briefly). Allow mixture to sit 3 minutes, then spin mixture at 1200 rpm,-5 minutes. Suction off supernatant. Gently resuspend pellet in 1 m DMEM A . Add the 1 m of DMEM A containing the cells to 10 DMEM^QA in bacteriological plate. Incubate overnight at 37°C. p ay 1 Spin down cells 800 rpm, 5 minutes. Resuspend pellet in 40 cc HAT medium. Aliquot 200 /well for two 96-well tissue culture plates (flat-bottomed). Day 2 Change medium of two plates (suck out half medium and add fresh HAT). Change HAT every other day (approximately). At about day 9 or 10, test visible clones for activity (you can wait longer if clones are small). At day 10 change medium to HT. When positive wells have become heavy, transfer them to cloning plates. Keep changing HT on original plates until all positive clones have been transferred to cloning * plates. Procedure for Cloning Take contents of one well (positive) and resuspend in 1 of HT medium in a polypropylene tube. Using a sterile tip, take 100 from the 1 m and fill two chambers of a heip-acytometer. Count cells—retain uncloned stock in culture as -a reserve. Make a stock solution of 5000 cells/m . Make four dilutions of cells: 50 cells/m (10 cells/well in 200 ); 25 cells/m (5 cells/well); 5 cells/m (1 cell/well); 2.5 cells/m (0.5 cell/well). Pour dilutions into small petri dishes. Aliquot 200 /well, 2 rows/dilution. Change medium once/week. When clones appear, test wells for activity. When positive wells have heavy growth. transfer contents of well to 0.5 cc HT medium in one well of 24 well plate. When growth heavy in 24 well plate transfer contents to 4 cc medium in T25 tissue culture flask. Cells can be frozen or expanded. Procedure for Freezing Cells: Starting c 5 cc cells suspended in medium they've conditioned, add 0.45 cc sterile DMSO. Using pipette, mix DMSO c cell suspension. Quickly transfer cells to freezing tubes (about 1 ml/tube). Transfer freezing tubes to a -80°C freezer to permit slow freezing. Then transfer frozen tube to a cane and then immediately into a liquid nitrogen freezer for long term storage. Some hybridoma lines have a tendency to stick to plates and may have to be trypsinized prior to freezing. Procedure for Thawing Cells Remove^designated tube from cane. Immediately place it in 37° H2O. As soon as cells are thawed, take contents of tube and add to 10 cc DMEM-I_Q « Spin down cells 800 rpm, 5 minutes. Resuspend pellet in DMEMJ_OA f° r culture. Procedure for Trypsinizing Cells (if necessary) Remove medium. Add sterile PBS o Ca ++ , Mg ++ . Remove PBS. Add trypsin solution (0.5 cc/T25, 1.5 cc/T75, 3 cc/T150). Let flask sit until cells come off bottom of flask (5-15 mins.). Add medium to flask and transfer contents to a sterile tube. Spin down 800 rpm, 5 minutes. Resuspend pellet in medium. Procedure for covalently linking proteins to Sepharose beads (method March et al. - Analyt. Bioch. , 60: 149-152, 1974) 1. Using a scintered glass funnel and vacuum, flask attached to a vacuum line, wash approximately 150 ml of Sepharose 4B CL with 5 liters of water to remove all traces of sodium azide. 2. Transfer the Sepharose to a 1 liter beaker and make a slurry 1 part Sepharose: 2 parts 2M Na2C0 3 . 3. Place the slurry in an ice bath on a magnetic stirrer in a hood. Stir until slurry is 7°C. 4. Add 1 ml of CNBr solution/10 ml Sepharose. Watch for precipitation of CNBr. Stir vigorously (or shake by hand) for 1-2 min after CNBr has gone back into solution. Drop pipet and all material that has CNBr on it into a large beaker containing several grams of NaOH pellets. Allow all material to sit for 24 hrs under the hood before discarding or cleaning. CNBr solution: 2 g CNBr/ml acetonitrile. Store frozen. 5. Pour the slurry into a scintered glass funnel attached to a vacuum flask. Wash with: 1.2 1 .1M NaHC0 3 pH 9.5 1.2 1 water 1.2 1 .2M NaHC0 3 pH 9.5 Do not let slurry dry during washing. 6. Pour or scrape the Sepharose into 1-2 g protein/120 ml .2M NaHC0 pH 9.5 at 4°C. 7. Shake vigorously for 2 hours at 20°C. 8. Add 9 g glycine and shake additional 1/2 hour. BΌREA 9. Wash in the scintered glass funnel with: 2 PBS 2 .1M NaAc, .5M NaCl pH 4.0 800 ml column buffer Specific Example: In the example presented here, hybridomas against HSA were made, one gram of mouse anti-HSA antibody was purified on a HSA-Sepharose column and these antibodies were coupled to Sepharose. Rat anti mouse IgG hybridomas were raised and one was chosen to grow in culture and purify on the mouse IgG column. This rat anti mouse IgG antibody was coupled to Sepharose and the affinity matrix was used to purify in a single step a mouse hybridoma directed against a guinea pig cell surface antigen. Mouse anti-HSA hybridomas: On May 19, 1980, ten balb/c mice were immunized with HSA in the manner described in the protocol above. They were boosted on June 16, 1980 and on July 10, 1980, two mice were given an IV injection of 40 mg each of HSA in preparation for the cell fusion. The fusion procedure was carried out on July 17, 1980 by the methods detailed above. The fused cells were maintained in culture in the manner described above until July 28, 1980 when the first series of clones were tested for production of antibody against HSA (method described above). The second series of clones were tested on August 7, 1980. Of the antibody producing clones that were detected, a total of nineteen were cloned and frozen for storage. One of these clones, designated OA10 was later chosen for expansion in large scale spinner culture for antibody production. Preparation of the HSA-Sepharose column: In order to purify the anti-HSA antibody from the tissue culture supernatant, an inert matrix with HSA coupled to the surface was required. Accordingly ten grams of HSA were purchased from Sigma Chemical Co. and four grams were used in each of two runs to make HSA-Sepharose by the method of March et al. as described above. A total of 240 cc of HSA-Sepharose beads were made and these were packed in a 44 x 300 mm column (Amicon Corporation) in preparation for purifying the mouse anti HSA antibody from the tissue culture supernatants. Production and Purification of Mouse IgG (Mouse anti HSA) One of the mouse anti-HSA clones, designated OA10, produced in the run described above was chosen for large scale spinner culture for antibody production. This clone was generally grown in 10 or 20 liter batches in commercially available (Bellco Glass Co.) ten liter spinner flasks. The cells were grown in DMEM supplemented to 5% with normal calf serum. Antibiotics were also added. After the cells had grown and died (about one week) the culture supernatant was centrifuged to remove cell debris and the clear supernatant was passed through the 240 cc HSA-Sepharose column. The column was then washed overnight with approximately four liters of PBS and the mouse antibody was removed from the column by running .1M glycine buffer (pH 2.5) through the column. After the protein peak had run off the column the glycine was neutralized with .25 volumes of 2M tris buffer (pH 8) and the antibody solution was stored at 4°C for future use. Sodium azide was added to a final concentration of .02% as a preservative. The amounts of mouse antiHSA antibody recovered from the HSA Sepharose column in ten such runs are given below. Mg of Antibody Date Recovered 1 9/26/80 64 2 10/16/80 66 3 10/27/80 48 11/07/80 97 5 11/18/80 116 6 12/02/80 92 12/18/80 108 8 12/31/80 185 9 1/14/81 136 10 1/28/81 108 A total of 1020 mg were recovered in a volume of 828 ml giving a concentration of 1.23 mg/ml. Prior to coupling this antibody to Sepharose, a more concentrated protein solution was required. Accordingly, the antibody solution was concentrated to 4.5 mg/ml but in the process 22% of the antibody was lost secondary to denaturation and precipitation. Preparation of the mouse IgG Sepharose: • Seven hundred and ninety-eight rag of mouse antibody remained in 176 ml of buffer. This antibody was mixed with 60 cc of cyanogen bromide activated Sepharose 4B (method of March et al. as described above). It was found that 100 rag of antibody remained unbound to the Sepharose which gave a coupling efficiency of 87.5%. This gave 11.63 mg of mouse antibody bound per cc of Sepharose beads. Preparation of the rat anti-mouse IgG hybridomas: On April 25, 1980, seven Lewis rats were each immunized with 200/ g of Mouse IgG (purchased from Cappel Laboratories) in the manner described above. They were boosted on May 29, June 20, July 29, August 22, and on September 11, 1980; two rats were given an I.V. injection of 200 g of mouse IgG in preparation for the cell fusion procedure. On September 15, 1980, the spleens of the two rats were removed, prepared as a single cell suspension and processed for cell fusion and subsequent culture by the methods described above. A total of 320 clones were detected and tested for production of rat antibody which bound to mouse IgG. Only nine producing clones were found and of these, only one, designated AHF5, was found to be useful for antibody production. This cell line was grown in ten liter spinner cultures ' and the antibody was purified on the mouse IgG sepharose column. Purification of the rat anti-iaouse IgG antibody on the mouse IgG Sepharose column: An initial batch of 20 liters of AHF5 culture supernatant was grown. - In experiments in which small amounts of culture supernatant were passed over small, amounts of the mouse IgG Sepharose beads, it was found that the rat anti mouse IgG antibody was present in the 0Λ1PI tissue culture supernatant at a concentration approximately 7 g/ml and one cc of mouse IgG. sepharose could bind 2.7 mg of rat anti mouse IgG antibody. Since there were 11.63 mg of mouse IgG per ml of Sepharose bead, this means that 23% of the mouse IgG molecules on the beads were in an orientation which permitted the binding of the rat anti-mouse IgG antibody. The 60 cc of Mouse IgG Sepharose was packed in a 22 x 300 mm Amicon column and approximately 14 liters of rat anti-mouse IgG culture supernatant was passed through the column. The column was washed with three liters of PBS and the rat anti-mouse IgG antibody was eluted from the column by passing .1 M glycine buffer (pH 2.5) through the column. The protein peak was neutralized with .25 volumes of 2M tris buffer (pH 8.0). Eighty mg of rat antimouse IgG antibody were recovered in 50 cc. - In preparation for coupling the Sepharose, the antibody was concentrated by ammonium sulfate precipitation. An equal volume of 100% saturated ammonium sulfate solution was added to the antibody and the mixture was gently stirred for one hour. The precipitate was centrifuged at 2000 RPM x 25 minutes. The precipitate was redissolved in 8 ml of PBS and dialyzed against .2M NaHC03, pH 9.5 (2L x 3). Ninety-one percent of the original antibody was recovered. Preparation of the rat anti-mouse IgG Sepharose: Seventy-three mg of rat antibody in 16 ml of .2 M bicarbonate buffer were mixed with 20 cc of cyanogen bromide activated Sepharose 4B-CL (method of "BURE ^ OMPJ March et al.). One and four tenths (1.4) mg of rat antibody did not bind to the activated Sepharose. Three and six tenths (3.6) mg of rat anti-mouse IgG antibody coupled per cc of Sepharose beads. Purification by affinity chromatography of a hybridoma antibody which interacts with an as yet unidentified cell surface antigen: As a component of an ongoing project, mouse hybridoma cell lines producing antibodies against a mixture of guinea pig cell surface antigens were produced and cloned by the methods outlined above. One of these clones, designated HA12, was choosen for antibody production in vitro. Approximately seven liters of culture supernatant were grown and after assessing the capacity of the rat anti-mouse IgG Sepharose column, the HA12 antibody was purified by affinity chromai^Dgraphy in one liter batches. The results of these runs are shown below. Purification of HA12 mouse anti guinea pig cell surface antigen on a 20 cc rat anti mouse IgG Sepharose column Amount of Antibody Amount loaded Recovered after washing Date on column and glycine elution 1. 4/14/81 1000 (cc) 20.9 mg 2. 4/15/81 1200 20.0 3. 4/16/81 800 18.3 "BU El^ OMPI 4. 4/17/81 900 17.8 5. 4/21/81 980 17.2 6. 4/22/81 940 18.2 7. 4/28/81 680 13. 0 The column used to purify the HA12 antibody is the same one prepared in the previous section. Thus 71.6 mg of rat antimouse IgG antibody were present on 20 cc of Sepharose beads. The total column capacity was 20.9 mg of mouse antibody. Thus 29% of the rat antibody molecules on the Sepharose, were oriented such that they were capable of binding a mouse antibody. From the foregoing it should be clear that the broad concept of^the invention is to utilize an inexpensive protein to produce a general affinity reagent for the purification of a .protein that occurs in very dilute solution. The foregoing example is directed to the ultimate production of a mouse monoclonal antibody utilizing human serum albumin as the inexpensive starting reagent. It should be appreciated, however, that the invention is applicable to the production of any protein which is produced in dilute solutions and the inexpensive starting material can be any protein which is capable of ultimately binding the protein sought for refinement. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present BU R£4 OMPI embodiments are therefore to be considered in all respects as illustrative and not restrictive,- the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. O. PI

Claims: Claims 1. A process for purifying specific antibodies by affinity chromatography comprising: A. producing a first hybridoma antibody capable of binding to an antigen? B. providing a column having immobilized thereon an antigen capable of binding the hybridoma antibody produced in step A; C. binding the hybridoma antibody of step A onto the column of step B; D. separating the first hybridoma antibody from the column of step C; E. immobilizing the first hybridoma antibody separated in step D on a column; F. producing a second hybridoma antibody capable of binding to the first hybridoma antibody; G. binding the second hybridoma antibody onto the first hybridoma antibody by passing the second hybridoma antibody through the column of step E; H. separating the second hybridoma antibody from the column of step G; 1. immobilizing the second hybridoma antibody separated in step H on a column; J. passing immunoglobulin specific to the second hybridoma through the column of step I to bind the immunoglobulins thereon; and, K. separating the bound immunoglobulin from the column of step J to obtain the purified immunoglobulin. 2. The process as ' set forth in claim 1 wherein in step B the column that is provided has immobilized thereon human serum albumin. " BlJRE4 OMPI 3. The process as set forth in claim 2 wherein the first hybridoma antibody produced in step A is a hybridoma producing mouse IgG. 4. The process as set forth in claim 1 wherein the second hybridoma produced in step F is the hybridoma producing rat anti-mouse IgG. 5. The process as set forth in claim 2 wherein the second hybridoma produced in step F is the. hybridoma producing rat anti-mouse IgG. 6. The process as set forth in claim 3 wherein the second hybridoma produced in step F is the hybridoma producing rat anti-mouse IgG. 7. The process as set forth in claim 4 wherein in step J the immunoglobulin is mouse immunoglobulin. 8. The process as set forth in claim 5 wherein in step J the immunoglobulin is mouse immunoglobulin. 9. The process as set forth in claim 6 wherein in step J the immunoglobulin is mouse immunoglobulin. 10. A process for purifying mouse immunoglobulin by affinity chromotography comprising: A. producing a hybridoma which produces mouse IgG which bonds to human serum albumim; B. providing a column having immobilized thereon human serum albumin; C. binding the mouse IgG of step A onto the column of step B; D. separating the mouse IgG from the column of step C; E. immobilizing the mouse IgG separated from step D onto a column; F. producing a hybridoma which produces rat anti-mouse IgG antibody; G. binding the rat anti-mouse IgG antibody onto the column of step E by passing the rat anti-mouse IgG antibody through the column of step E; H. separating the rat anti-mouse IgG from the column of step G; I. immobilizing the rat anti-mouse IgG antibody separated in step H on a column; J. passing mouse immunoglobulin through the column of step I to bind the immunoglobulins thereon; and, K. separating the bound immunoglobulins of step J from the column to obtain purified immunoglobulins. "BU E ΛT OMPI ~

Inventors: KADISH JULIAN L, KADISH, JULIAN, L.
Applicants: BETH ISRAEL HOSPITAL, THE BETH ISRAEL HOSPITAL ASSOCIATION
Application year: 1982
Main classification: C12N5
IPC codes: C07K16