Fusion is an important procedure to produce monoclonal antibodies (MoAb). PROTOCOL

prepare the culture of myeloma cells and maintain the concentration of the cells at the level of less than 10^6 cells/ml (IMDM + 10% FCS/FBS). Just before the fusion wash 3 times in IMDM (serum free!), 1200 rpm, 5min, 37?C. Count cells. sacrifice the mouse and dissect the spleen. tease the spleen in ice-cold IMDM (serum free!); pass through the nylon? filter; wash 3 times in IMDM (serum free!), 1200 rpm, 5min, 37?C. Count cells. mix 10^8 spleen cells (in 25 ml of IMDM [serum free]) with 2x10^7 myeloma cells (in 25 ml of IMDM [serum free]) in Falcon-50 ml conical tube. centrifuge at 1200 rpm, 5 min, 37?C. aspirate the supernatant (SN) with a Pasteur pipette (all till the last drop!!!) gently break the pellet by tapping of the bottom of the tube. place the tube on 37?C water bath; add slowly, dop by drop 1 ml of pre-warmed (37?C) 50% PEG 1500 (polyethylene glycol, Roche, Germany) continously stirring the cells with the pipette tip (this procedure lasts for a period over 1 min) add 1 ml of pre-warmed to 37?C IMDM continously stirring the mixture (this procedure lasts for a period over 1 min). add 3 ml of pre-warmed to 37?C IMDM continously stirring the mixture (this procedure lasts for a period over 3 min). add 10 ml of pre-warmed to 37?C IMDM continously stirring the mixture (this procedure lasts for a period over 1-2 min). let to stay for 5 min on the 37?C water bath. centrifuge at 1200 rpm, 5 min, 37?C; aspirate the SN. resuspend the cells in IMDM-FCS(10%v/v) - HTx100 (1%v/v) - AJ(5%v/v) - IL-6, 0.5x10^6 cells/ml (calculation figured out from the number of spleen cells the fusion was started from); let to stay in incubator, 37?C, pCO2 7% for 2 hours in a big flasc. add aminopterin; distribute on 96-wells cell culture plates (Nunc) (200μl/well); place in incubator (37?C, pCO2 7%) enveloped in aluminium paper. check the cultures 1-2-7 days after the fusion. on day 7-10 change the culture medium. test clones when thay occupy 25% of the bottom surface of the well. SOLUTIONS IMDM (Iscove's Modified Dulbecco's Medium with 25 mM Hepes/with L-Glutamine) BioWhittaker Europe Cat.: BE12-722F IMDM-FCS(10%v/v)-HTx100(1%v/v)-AJ(5%v/v)-IL-6 (100 U/ml) IMDM - FCS(10%v/v) - HTx100(1%v/v) - AJ(5%v/v) - IL 6 (100 U/ml) - aminopterine x100 (1% v/v) HT (hypoxantine-thymidine)x100, 0.22 (or 0.45) μm-filtered, store at -20?C = hypoxantine solution, 50 ml + thymidine solution, 50 ml + ddH2 O up to 250 ml hypoxantine solution = hypoxantine, 340 mg + ddH2 O up to 50 ml + NaOH 1 N, 3 ml -> heat to 37?C thymidine solution = thymidine (2'-desoxy-thymidine), 96 mg + ddH2 O up to 50 ml AJ (from "ajouter" , to add, local slang), 3 L, 0.22 (or 0.45) μm-filtered, store at -20?C =? Asp-Arg x100, 1 L + Gluta x 50, 2 L + mercaptoethanol, 350 μl Asp-Arg x100, 1 L, pH 6.0 = L-Asparagine, 3.6 g (0.24 mM) + L-Arginine (0.55 mM), 11.6 g + HCl, 0.5N, 100 ml -> heat to 37?C, add ddH2 O up to 1 L Gluta x50, 1 L, pH 6.0 = glutamine, 10.8 g (1.48 mM) + HCl, 0.5N, 100 ml -> heat to 37?C, add ddH2 O up to 1 L aminopterine x100, 0.22-0.45 μm-filtered, store at -20?C = aminopterine, 4.4 mg (3.8μM)+ ddH2 O, 50 ml + NaOH, 1N, 100 μl-> heat to 37?C, add ddH2 O up to 250 ml

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