When the optic density reached a value of 0.6, the culture was induced with isopropylthiogalactoside
0.1 M (Gibco BRL, Gaithersburg, MD, UsA) and incubated at 30[degrees] C under agitation for 4 h.
coli BL21 (DE3) GOLD carrying pET28a-SCO1678 was grown in LB supplemented with tetracycline and kanamycin until OD600 reached 0.5; then the culture was induced with 1mM IPTG (isopropylthiogalactoside
) and incubated for six hours at 22[degrees]C.
The overnight culture was transferred to 225 mL 2 x YT broth and grown with shaking to midlog phase ([A.sub.600] 0.6) before inducing TbHsp70.c protein expression by the addition of isopropylthiogalactoside
(IPTG) to a final concentration of 1 mM.