valley blvd san diego calif 92121 to confirm correct sequences in plasmids constructed the ligation mixtures are used to transform e coli k12 strain dh5a atcc 31446 and successful transformants selected by antibiotic resistance where appropriate plasmids from the transformants are prepared analyzed by restriction and or sequence by the method of messing et al nucleic acids res 4 309 1981 host cells may be transformed with the expression vectors of this invention and cultured in conventional nutrient media modified as is appropriate for inducing promoters selecting transformants or amplifying genes the culture conditions such as temperature ph and the like are those previously used with the host cell selected for expression and will be apparent to the ordinarily skilled artisan the techniques of transforming cells with the aforementioned vectors are well known in the art and may be found in such general references as maniatis et al molecular cloning a laboratory manual cold spring harbor press cold spring harbor laboratory cold spring harbor n y 1989 or current protocols in molecular biology 1989 and supplements preferred suitable host cells for expressing the vectors encoding the claimed proteins in higher eukaryotes include african green monkey kidney line cell line transformed by sv40 cos 7 atcc crl 1651 transformed human primary embryonal kidney cell line 293 graham f l et al j gen virol 36 59 72 1977 virology 77 319 329 virology 86 10 21 baby hamster kidney cells bhk 21 c 13 atcc ccl 10 virology 16 147 1962 chinese hamster ovary cells cho dhfr atcc crl 9096 mouse sertoli cells tm4 atcc crl 1715 biol reprod 23 243 250 1980 african green monkey kidney cells vero.