Aedes aegypti cells (Grace's line) growing in a medium containing 5% Antheraea pernyi hemolymph (APH) and 5% fetal bovine serum (FBS) were adapted to a hemolymph-free medium. The quantity of APH was gradually substituted with an equal quantity of FBS over a 2-month period. The cells grew very slowly in the hemolymph-free medium in the beginning. However, they became adapted to it in another 8 months; after that they grew as well as the cells in medium supplemented with hemolymph.Also, these cells grew as well in medium containing Bombyx mori hemolymph as in medium enriched with APH.