Increased human hybridoma formation by electrofusion of human B cells with heteromyeloma SPAM-8 cells.

A fusion protocol was designed for the optimal production of hybridomas following electrofusion of human B cells with cells of the heteromyeloma fusion partner SPAM-8. Peripheral blood lymphocytes showed an average fusion efficiency of 0.4 x 10(-4) whereas Epstein-Barr virus-transformed B cells showed fusion efficiencies ranging from 6.2 x 10(-4) to 9.0 x 10(-4). Similar results were obtained with bone marrow-derived lymphocytes. Trypsin treatment of the cells prior to electrofusion further increased the fusion efficiency to 12.3 x 10(-4). In comparison, conventional polyethylene glycol-induced fusion resulted in a fusion efficiency of 0.8 x 10(-4). Thus, electrofusion of human B cells with SPAM-8 heteromyeloma cells introduced a 15-fold increase in hybridoma formation as compared to the conventional fusion method.