A great improvement of fusion efficiency in mouse B cell hybridoma production by use of the new culture medium, GIT.

The recently established culture medium, GIT, is applicable to many kinds of cells including mouse and human myeloma cells, and most adhesive cell lines. We applied this GIT medium to mouse B cell hybridoma production. When the medium was used to propagate myeloma cells before cell fusion and also for HAT selective medium, the fusion efficiency was more than twice as high as when the regular medium (RPMI-1640 supplemented with FBS) was used. Constantly more than 80% wells were hybridoma positive irrespective of the antigens used. To determine the optimal cell concentration at the hybridoma selection, a graded number of myeloma and spleen cells was distributed to each well; the best result was obtained when 3 X 10(4) myeloma and 3 X 10(5) spleen cells were distributed to each well. In addition, the GIT medium shows very little lot-to-lot variation. These results indicate that fusion efficiency in mouse B cell hybridoma production was greatly improved by using GIT medium.