Improved fusion technique. II. Stability and purity of hybrid clones.

Optimal conditions are defined for hybridoma formation between mouse spleen cells and mouse myeloma cells. The results of using different numbers of spleen cells in the fusion process is reported in 2 parts. Part I deals with the number of spleen cells in relation to hybridoma formation and antibody production.

Improved fusion technique. III. The growth promoting activity of lipopolysaccharide, dextran sulfate, and red cell lysate added to Hy-clone calf serum.

A new high quality young-calf serum, Hy-clone calf serum (HcCS), was tested for use in hybridoma culture. This calf serum alone had little growth promoting activity and was much inferior to fetal calf serum (FCS). Red cell lysate (RCL) used in combination with the young-calf serum showed very good growth promoting activity.

Improved fusion technique. I. Human umbilical cord serum, a new and potent growth promoter, compared with other B cell and hybridoma activators.

Accelerated proliferation of hybridoma cells was observed in the presence of human umbilical cord serum (HUCS). This had very strong growth-promoting activity, even at a concentration of 2%. A comparison was made between HUCS and other B cell growth promoters, such as lipopolysaccharide (LPS) and dextran sulfate (DxS), macrophage supernatant, and human endothelial culture supernatant (HECS).