The invention relates to a method of increasing protein expression in baculo
vector virus expression systems. The invention provides a method to produce a recombinant
protein in insect cell culture which comprises selecting a recombinant baculovirus
expressing said protein, growing insect cells in growth medium in a culture vessel
and infecting the cells with an inoculum of at least one baculovirus at a cell
density of 1105 to 5106 cells/ml with an m.o.i
of <0.01. The invention also provides a method to produce recombinant pestivirus
E2 or Em9 protein or fragments thereof in insect cell culture characterized
by a final concentration of the protein fragments in the growth medium at harvest
of at least 100 g/ml. The invention also provides a method of producing
recombinant FSH, -units and/or -units, and complexes and fragments
thereof, at a concentration in the growth medium at harvest of at least 15 /ml.
