Comparison of polyethylene glycols as fusogens for producing lymphocyte-myeloma hybrids

In order to improve the yield of hybridomas for monoclonal antibody production, 8 different sources and molecular weights of polyethylene glycol (PEG) were compared as fusing agents. Sp2/0 myeloma cells were fused with murine splenic lymphocytes immunized with sheep red blood cells. The Kodak 1450 PEG produced the maximum number of hybridomas. The optimal technique consisted of slowly adding 1 ml of freshly prepared fusogen (5 g Kodak 1450 PEG, 0.5 ml dimethylsulfoxide, and 5 ml of phosphate-buffered saline, pH 7.0) to the cells over a 1 min period, incubating the mixture at 37 degrees C for 90 s, then gradually diluting the mixture in 50 ml of Hanks' buffered salt solution. After 10 min, the cells are centrifuged, resuspended in selective medium with feeder macrophages and cultured. This procedure routinely produces between 600-3,000 hybridomas per fusion.